Generic Revision in the Holarctic Ground Squirrel Genus SpermophilusDOI: info:10.1644/07-MAMM-A-309.1v. 90No. 2ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS270–305
Helgen, Kristofer M., Cole, F. Russell, Helgen, Lauren E., and Wilson, Don E. 2009. "Generic Revision in the Holarctic Ground Squirrel Genus Spermophilus." Journal of mammalogy, 90, (2) 270–305. https://doi.org/10.1644/07-MAMM-A-309.1.