According to the biography posted at utmost.org-
Oswald Chambers was not famous during his lifetime. At the time of his death in 1917 at the age of forty-three, only three books bearing his name had been published. Among a relatively small circle of Christians in Britain and the U.S., Chambers was much appreciated as a teacher of rare insight and expression, but he was not widely known.It is said - behind every great man there's a great woman. According to Oswald's page on Wikipedia-
While there are more than 30 books that bear his name, he only penned one book, Baffled to Fight Better. His wife, Biddy, was a stenographer and could take dictation at a rate of 250 words per minute. During his time teaching at the Bible College and at various sites in Egypt, Biddy kept verbatim records of his lessons. She spent the remaining 30 years of her life compiling her records into the bulk of his published works.Oswald's words are a timeless gift from God.
Additional links -
The Quotable Oswald Chambers with My Utmost – The Oswald Chambers Story DVD
Oswald Chambers—Abandoned to God (Paperback) by David McCasland