The Course of Theoretical Physics is a ten-volume series of books covering theoretical physics that was initiated by Lev Landau and written in collaboration with his student Evgeny Lifshitz starting in the late 1930s.It is said that Landau composed much of the series in his head while in an NKVD prison in 1938-39. However, almost all of the actual writing of the early volumes was done by Lifshitz, giving rise to the often repeated witticism, "not a word of Landau and not a thought of Lifshitz".