Geoffrey L. Lewis is a distinguished scholar of the Turkish language and the author of several well known books about Turkish. Many people have learned Turkish from his "Teach Yourself Turkish" and used as a reference his "Turkish Grammar". Lewis was born in London, England in 1920 and educated at the University College School and St John's College, Oxford. Wikipedia
The definitive Wikipedia entry for Geoffrey Lewis. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Geoffrey_Lewis_%28Turkish_scholar%29