But I remained rather poor until the book on education in 1926. After that, until 1933, I prospered financially, especially with Marriage and Morals (1929) and The Conquest of Happiness (1930) . Most of my work during these years was popular, and was done in order to make money, but I did also some more technical work.
Source:The Autobiography of Bertrand Russell, v.2 chap. 4: Second Marriage, 1968
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