1. Subspeciation in Haemonchus contortus (Rudolphi 1803). Nemata, Trichostrongyloidea;Das;The Cornell Veterinarian,1960
2. On the morphologic diversity of the female Haemonchus contortus (Rudolphi 1803) Cobb 1898 and Haemonchus placei (Place 1893) Ransom 1911;Daskalov;Bulletin of the Central Helminthological Laboratory, Bulgarian Academy of Sciences,1963
3. The intraspecific structure of Haemonchus contortus (Rudolphi 1803) Cobb 1898. III. Experiments for elucidating the genetics of female Haemonchus;Daskalov;Bulletin of the Central Helminthological Laboratory, Bulgarian Academy of Sciences,1969