City of Gardner
Gardner Chamber of Commerce
Kansas Travel & Tourism
"Dropping the Bucket and Sponge", a book by Matt J. Webber, featuring Cramer Products/Cramer Chemical.
Johnson County GenWeb Site
JoCoHistory.net- "a collaborative presentation of the history of Johnson County, Kansas from the Johnson County Museum and Partners."
Edgerton, KS History
Santa Fe Trail
Oregon-California Trails Association