1. Intraspecific variation in parasitic nematodes;Chitwood;Systematic Zoology,1957
2. On the intraspecific structure of Haemonchus contortus (Rudophi, 1803) Cobb, 1898. I. Experiments for the isolation and maintenance of morphologically pure strains;Daskalov;Bulletin of the Central Helminthological Laboratory, Bulgarian Academy of Sciences,1968
3. On the intraspecific structure of Haemonchus contortus (Rudolphi, 1803) Cobb, 1898. II. Experiments for crossing morphologically isolated monotype strains with a linguiform flap and a knoblike process;Daskalov;Bulletin of the Central Helminthological Laboratory, Bulgarian Academy of Sciences,1969
4. On the intraspecific structure of Haemonchus contortus (Rudolphi, 1803) Cobb, 1898. III. Experiments for elucidating the gentic conditionality of smooth female Haemonchus;Daskalov;Bulletin of the Central Helminthological Laboratory, Bulgarian Academy of Sciences,1969
5. Seasonal fluctuation in linguiform morphs of Haemonchus contortus cayugensis;LeJambre;Journal of Parasitology,1968