171. tetrao-perdrix nivicola, ii.
"Himalayan Journals V2."
J. D. Hooker
The appearance of the dove-like grouse, tetrao paradoxus, or Syrrhaptus Pallassi, in various parts of Europe, in 1850 and the following years, is a noticable exception to the law of regularity which seems to govern the movements and determine the habitat of birds.
"The Earth as Modified by Human Action"
George P. Marsh