b- Bruno Mosaingeon, Sviatoslav Richter: Notebooks and Conversations, translated by Stewart Spencer, Princeton University Press, 2001 [2]

2- Leong Yan Hoi

"In the book Sviatoslav Richter: Notebooks and Conversations by Bruno Mosaingeon, Richter mentioned that not only was his perfect pitch altered by a full tone in his old age, but that the same thing happened to his teacher, the great pedagogue Heinrich Neuhaus.  He went on to say that the main reason why he played with a score in his last years was that because of this altered pitch he tended to transpose automatically when playing from memory, and was thus afraid of presenting musical pieces in the wrong key to the audience." [2]