Conversation so far:
how did the program help Bll W.?
He then had the sensation of a bright light, a feeling of ecstasy, and a new serenity.
He never drank again for the remainder of his life.
how long ws he in the program?
CANNOTANSWER.
what did Bill accomplish while in the spirtual program?
Wilson returned to New York where he began having success helping alcoholics in what they called "a nameless squad of drunks" in an Oxford Group there.
how did he help others with alcohol??
through the publication of a book, for which Wilson was chosen as primary author.

Question: what was the name of the book?
Self-contained rewrite: what was the name of Bll Wilson's book?