Studies In Romance Philology And Literature, 1966, Garnett Publishing Words in Sheep's Clothing, 1969 Talking Your Way Around the World, 1971, Harper-Collins, Getting along in Spanish, 1972, Bantam Weasel Words, 1972, Harper & Row
Families of Words, 1974, St Martins Press, 0312280351 Dictionary Of Foreign Terms, 1975, Delacorte Press, What's In A Word? Language: yesterday, today, and tomorrow, 1975, Universal The Story of Latin and the Romance Languages, 1976, Harper-Collins, New Italian Self-Taught, 1982, Harpercollins,
Języki obce Medieval Romance Poetry, 1961 (Folkways Records) One Language for the World, 1961 (Folkways) Getting Along in Russian, Vol. 1, 1962 (Folkways) Getting Along in Russian, Vol. 2, 1962 (Folkways) Getting Along in French, Vol. 1, 1962 (Folkways) Readings in Church Latin – Caesar and Cicero: Read by Dr. Mario A. Pei, 1962 (Folkways) Readings in Church Latin – Virgil and Horace: Read by Dr. Mario A. Pei, 1962 (Folkways) Getting Along in English, Vol. 1, 1964 (Folkways)