Arctische wolf
The arctic wolf. social behavior, habitat, breeding, and endangerment of the arctic wolf
http://www.cosmosmith.com/arctic_wolves.html
Grijze wolf
The gray wolf of north america. social behavior, habitat, breeding, and endangerment of the gray wolf
http://www.cosmosmith.com/gray_wolves.html
Mexicaanse wolf
The mexican gray wolf - lobos. social behavior, habitat, breeding, and endangerment of the mexican gray wolf
http://www.cosmosmith.com/mexican_wolves.html
Rode wolf
The red wolf of north america. social behavior, habitat, breeding, and endangerment of the red wolf
http://www.cosmosmith.com/red_wolves.html