Reference sources for individual saints:

Bernadette of Lourdes
Bernadette Speaks: A Life of Saint Bernadette Soubirous in Her Own Words, René Laurentin (translated from the French by John W. Lynch, S.M., and Ronald DesRosiers, S.M.), Pauline Books & Media, 2000.

Catherine of Siena
Catherine of Siena: A Passionate Life, Don Brophy, BlueBridge (United Tribes Media Inc.), 2010.
Little Lessons from the Saints: 52 Simple and Surprising Ways to See the Saint in You, Bob Burnham, Loyola Press, 2017.

Cecilia
“La cathédrale Sainte-Cécile d’Albi” (brochure), Editions Odyssée.
Rick Steves France 2016, Rick Steves and Steve Smith, Avalon Travel Publishing, 2015.

Clare of Assisi
• Clare of Assisi: The Letters to Agnes, Joan Mueller, O.S.F., Liturgical Press, 2003.
Little Lessons from the Saints: 52 Simple and Surprising Ways to See the Saint in You, Bob Burnham, Loyola Press, 2017.
Poor Clare Sisters of Spokane.
Rick Steves Italy 2019, Rick Steves, Avalon Travel (Hachette), 2018.

Edith Stein
Edith Stein: A Biography, Waltraud Herbstrith, O.C.D. (translated by Father Bernard Bonowitz, O.C.S.O.), Ignatius Press, 1992.
Edith Stein: Selected Writings, Susanne M. Batzdorff, Templegate Publishers, 1990.
An Hour with Edith Stein, John Sullivan, O.C.D., Liguori Publications, 2006.

Germaine Cousin
• “Germaine Cousin,” https://en.wikipedia.org/wiki/Germaine_Cousin.
• “Scrofula,” website of Mount Sinai Health Systems, New York: https://www.mountsinai.org/health-library/diseases-conditions/scrofula#.

Hildegard von Bingen
Hildegard of Bingen: Selected Writings (translated with an introduction and notes by Mark Atherton), Penguin Books, 2001.
Illuminations (fiction based on historical analysis), Mary Sharratt, Mariner Books, 2012.

Ignatius of Loyola
The Ignatian Adventure: Experiencing the Spiritual Exercises of St. Ignatius Loyola in Daily Life, Kevin O’Brien, S.J., Loyola Press, 2011.
• “Saint Ignatius Loyola” (article), www.IgnatianSpirituality.com, Loyola Press.
• “What Are the Spiritual Exercises of Saint Ignatius?” (article), Joe Paprocki, D.Min., www.LoyolaPress.com.

Joan of Arc
Joan of Arc: A History, Helen Castor, Harper, 2015.

Julian of Norwich
“Coronavirus: Mystic’s ‘relevance’ to self-isolating world,” by Nic Rigby, BBC News, March 30, 2020.
Julian of Norwich: A Contemplative Biography, Amy Frykholm, Paraclete Press, 2018.

Mary
Agia Dynamis (article and photo), The Athens Key.
Dinner with Persephone: Travels in Greece, Patricia Storace, Vintage Departures, 1997.
Mary Through the Centuries: Her Place in the History of Culture, Jaroslav Pelikan, Yale University Press, 1996.

Teresa of Avila
• The St. Teresa of Avila Prayer Book, Vinita Hampton Wright, Paraclete Press, 2015.
• Teresa of Avila: The Progress of a Soul,
Cathleen Medwick, Image, 2001.

Therese of Lisieux
Pearls of Wisdom: Praying the Spiritual Journey of St. Thérèse of Lisieux (novena booklet), M. Susan Lautenbach, Society of the Little Flower.

Reference sources for saints in general:

• The Pilgrim’s France: A Travel Guide to the Saints, James and Colleen Heater, Inner Travel Books, 2004.
• The Pilgrim’s Italy: A Travel Guide to the Saints, James and Colleen Heater, Inner Travel Books, 2003.
www.Wikipedia.org, Wikimedia Foundation.

Learn about the saints in their own words:

Bernadette of Lourdes
A Holy Life: The Writings of St. Bernadette of Lourdes, Patricia McEachern, Ignatius Press, 2005.
Bernadette Speaks: A Life of Saint Bernadette Soubirous in Her Own Words, René Laurentin (translated from the French by John W. Lynch, S.M., and Ronald DesRosiers, S.M.), Pauline Books & Media, 2000.

Catherine of Siena
• Catherine of Siena: The Dialogue (Classics of Western Spirituality), Suzanne Noffke, O.P. (translator), Paulist Press, 1980.
• The Letters of Catherine of Siena, Vol. 1,
Suzanne Noffke O.P. (translator), ACMRS, 2000.
• The Letters of Catherine of Siena, Vol. 2, Suzanne Noffke O.P. (translator), ACMRS, 2000.
• The Prayers of Catherine of Siena, Suzanne Noffke, O.P. (translator), iUniverse, 2001.

Clare of Assisi
Clare of Assisi: The Letters to Agnes, Joan Mueller, O.S.F., Liturgical Press, 2003.

Edith Stein
Edith Stein: Selected Writings, Susanne M. Batzdorff, Templegate Publishers, 1990.
Essays on Woman, ICS Publications, 1996.
Finite and Eternal Being: An Attempt to an Ascent to the Meaning of Being, ICS Publications, 2002.
Life in a Jewish Family (Edith Stein’s unfinished autobiography), ICS Publications, 1999.
On the Problem of Empathy, ICS Publications, 1989.
Philosophy of Psychology and the Humanities, ICS Publications, 2000.
The Science of the Cross, ICS Publications, 2003.

Hildegard von Bingen
Hildegard of Bingen: Selected Writings (translated with an introduction and notes by Mark Atherton), Penguin Books, 2001.
• “11,000 Virgins – Chants for the Feast of St. Ursula” (music), Hildegard von Bingen (performed by Anonymous 4), label: harmonia mundi, 2005.
• “Canticles of Ecstasy” (music), Hildegard von Bingen (performed by Sequentia), label: deutsche harmonia mundi, 1994.
• “The Dendermonde Codex” (music), Hildegard von Bingen (performed by Dous Mal), label: etcetera, 2009.
• “Ordo Virtutum” (music), Hildegard von Bingen (performed by Sequentia), label: deutsche harmonia mundi, 1998.
• “The Origin of Fire” (music), Hildegard von Bingen (performed by Anonymous 4), label: harmonia mundi, 2006.

Ignatius of Loyola
The Ignatian Adventure: Experiencing the Spiritual Exercises of St. Ignatius Loyola in Daily Life, Kevin O’Brien, S.J., Loyola Press, 2011. (I recommend this modern guide to the Exercises as an entry point to understanding Ignatius’ writings.)
• Full text of The Spiritual Exercises of St. Ignatius of Loyola (translated by Elder Mullan in 1914), http://sacred-texts.com/chr/seil/index.htm.

Joan of Arc
Joan of Arc: By Herself and Her Witnesses, Régine Pernoud (translated from the French by Edward Hyams), Scarborough House, 1994.

Julian of Norwich
Revelations of Divine Love (Short Text and Long Text), Julian of Norwich (translated by Elizabeth Spearing), Penguin Books, 1999.

Teresa of Avila
Autobiography of St. Teresa of Avila, Dover Publications, 2010.
Interior Castle, St. Teresa of Avila (translated and edited by E. Allison Peers), Dover Publications, 2007.
The Way of Perfection, St. Teresa of Avila (edited by E. Allison Peers), Dover Publications, 2012.

Therese of Lisieux
Story of a Soul: The Autobiography of St. Thérèse of Lisieux (third edition, translated from the original French manuscripts by John Clarke, O.C.D.), ICS Publications, 1996.
Maurice & Thérèse: The Story of a Love, Patrick Ahern, Image/Doubleday, 1998.