http://olivercowdery.com/smithhome/smithtx6.htm
http://www.boap.org/LDS/Early-Saints/DWillers.html
D. Michael Quinn, trans. and ed., “The First Months of Mormonism: A Contemporary View by Rev. Diedrich Willers,” New York History 54 (July 1973):317-33. 1830. Diedrich Willers Letter (1830).
http://www.boap.org/LDS/Early-Saints/DWillers.html