Complex sentence: He married his second wife, Evelyn Bostwick in 1920 (Bostwick's daughter from a previous marriage was Joe Carstairs), who translated Voronoff's book, "Life: a means of restoring vital energy and prolinging life", into English.
Split into simpler sentences: He married his second, Evelyn Bostwick in 1920 (Bostwick's daughter from a previous marriage was Joe Carstairs). Evelyn translated Voronoff's book, "Life: a means of restoring vital energy and prolinging life", into English.