Lidiya Markovna Yanovskaya (1926–2011), a famous literary critic and text critic, author of numerous publications that for the first time introduced into literature the works, documents, facts of life and creativity of the greatest writers of the twentieth century - Mikhail Bulgakov, Ilya Ilf and Evgeny Petrov. L. Yanovskaya devoted more than one decade of her life to researching the life and work of Bulgakov. She managed for the first time to restore the complete texts of the novels “The White Guard” and “The Master and Margarita”, the story “The Heart of a Dog”, and also compiled and prepared for publication “The Diary of Elena Bulgakova”. Her major, final work “The Last Book, or Woland’s Triangle” , on which the researcher worked until the last days of her life, is dedicated to both the mysteries of the great writer’s “sunset romance” and the most significant and little-studied facts of his biography and creative life.