Prayer

1. "A Simple Way to Pray" by Martin Luther - Luther's classic work provides a straightforward, accessible approach to prayer. It's particularly known for Luther's method of using the Lord's Prayer, the Ten Commandments, and the Apostles' Creed as guides for structuring prayer.
2. "Prayer" by John Bunyan - Bunyan, best known for "Pilgrim's Progress", also wrote extensively on prayer. His works are deeply insightful, encouraging a heartfelt, sincere approach to communicating with God.
3. "The Secret Key to Heaven" by Thomas Brooks - As a prominent Puritan preacher and author, Brooks offers a rich, scripture-based perspective on prayer. His writing is known for its depth, practicality, and emphasis on the experiential aspects of faith.
4. "A Praying Life" by Paul E. Miller - You've mentioned this one earlier, and it's certainly worth reiterating. Miller's book is highly regarded for its practical advice on integrating prayer into everyday life amidst the distractions and challenges of the modern world.
5. "A Method For Prayer" by Matthew Henry - Henry, a renowned biblical commentator, provides a comprehensive guide to prayer in this work. It's structured around various themes and includes a wealth of scripture, making it a valuable tool for deepening one's prayer life.
6. "The Valley of Vision: A Collection of Puritan Prayers & Devotions" edited by Arthur Bennett - A classic collection of prayers and devotions. These prayers are deeply theological yet intensely practical, reflecting a high view of God and a deep understanding of human need.
7. "Praying the Bible" by Donald S. Whitney - Whitney offers a simple, yet profound method for invigorating your prayer life: praying through the words of Scripture. This approach helps to focus prayer and align it with biblical truth.
8. "Prayer" by John Calvin - Part of Calvin's seminal work, "Institutes of the Christian Religion", this section on prayer is rich in theological insight and practical wisdom. It provides a deep dive into the Reformed understanding of prayer.
9. "Does Prayer Change Things?" by R.C. Sproul - This book tackles one of the most important questions about prayer. Sproul, a respected theologian, provides a biblically grounded answer that underscores the power and purpose of prayer.
10. "The Chief Exercise of Faith: John Calvin on Prayer" by John Calvin - This book is a compilation of Calvin's teachings on prayer, offering insights into his thoughts and practical advice on how to engage in meaningful prayer.
11. "The Power of Prayer in a Believer's Life" by Charles H. Spurgeon - Known as the "Prince of Preachers," Spurgeon's writings on prayer are as passionate and powerful as his sermons. This book is a collection of his thoughts on the importance and efficacy of prayer.

Remember, while these books offer valuable insights and guidance, the practice of prayer is deeply personal and grows through regular, heartfelt engagement with God.