Order Rodentia - Family Sciuridae Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2 754 818 book chapter 0-8018-8221-4 10.5281/zenodo.7316535 Spermophilus undulatus subsp. transbaikalicus Obolenskii 1927 Synonyms: Spermophilus undulatus subsp. intercedens (Ognev 1937) .