Clay Times Three (2009) is the only book offering a published biography of Karl Martz and Becky Brown -- and it is outstanding! This labor of love is by Kathy M. McKimmie, a free-lance author in Indianapolis, Indiana. She researched three 20th century Brown County, Indiana potteries in considerable depth, including the various phases of the Karl Martz and Becky Brown potteries, as well as the Brown County and Brown County Hills potteries. She has done a wonderful job of weaving the lives of Karl and Becky into a well-documented, coherent and engaging story. Her careful research and thorough documentation are outstanding. I learned a few things I didn't know about my own parents when reading it! This is the first book to document any of these three potteries, and it includes 182 photographs, most in color. -Eric Martz, December 14, 2009. (2019: This book is out of print, but the ebook is available via the Indiana University Press.)