. . . . . . . "Variations and genetic relationships of the garter-snakes, by Alexander G. Ruthven" . "This paper is an attempt to do classification on the garter-snake group to help define differences between natural groups and clarify the systematic arrangements."@en . . . . . . "Variations and Genetic relationships of the Garter-Snakes"@en . . "Variations and genetic relationships of garter-snakes"@en . . "Variations and Genetic relationships of the Garter-Snakes" . . . "Variations and genetic relationships of the garter-snakes"@en . . . "Variations and genetic relationships of the garter-snakes" . "Three steps are necessary to determine the genetic relationships: (1) The value of the defining characters must be determined; (2) the geographic probabilities must be utilized; (3) similarities and intergradations must be sought."@en . . . . . . . "Classification"@en . . . "Kače Zoologija." . . . . "région néarctique (zoogéographie) Thamnophis (Colubridae, Serpentes)" . . "région néarctique (zoogéographie) Thamnophis (Colubridae, Serpentes) variation géographique." . .