Uta Hagen's memoir, "Sources," explores the formative experiences and artistic philosophies that shaped her legendary career as an actress and acting teacher. Drawing from her personal life, including her childhood in Germany, her early theatrical training, and her experiences in the American theater, Hagen details the influences that guided her approach to acting. The book presents her insights into the craft, emphasizing authenticity, emotional truth, and the rigorous discipline required for performance.

Uta Hagen's "Sources" is regarded as a significant work for actors and theater enthusiasts, offering a direct look into the mind of a master practitioner. The memoir is valued for its candid reflections on the artistic process and the personal journey that informed Hagen's influential teaching. It provides a window into the development of her renowned acting techniques, making it a foundational text for understanding her contributions to the craft.