Comments on the distribution and subspecies classification of Parnassius cephalus Grum-Grshimailo, 1891 and P. acdestis Grum-Grshimailo, 1891 in Tibet. Nachrichten des Entomologischen Vereins Apollo, 17(4), Februar 1997: 393-404. 402 [Zoological Record Volume 133]