American English: Dialects and Variation - Walt Wolfram, Natalie Schilling-Estes - Google Books

http://books.google.de/books?id=zVj5_TRHQpYC&pg=PA143&dq=American+regional+dialects:+A+word+geography.&hl=de&ei=zDrgTJzjK42L4QaS

This book provides a very readable, up-to-date description of language variation in American English, covering regional, ethnic, and gender-based differences.contains new chapters on social and ethnic dialects, including a separate chapter on African…