1. Distribution of Carduus nutans, C. acanthoides, C. pycnocephalus, and C. crispus in the United States;Dunn;Weed Sci.,1976
2. History of the biological control of musk thistle in North America and studies with the flea beetle Psylliodes chalcomera;Dunn,1978
3. Ceuthorhynchus (Hadroplontus) trimaculatus(F.) and Ceuthorhynchidius horridus (Panzer), two weevils of potential value for the biological control of thistles in the genus Carduus L;Frick,1969
4. Carduus acanthoides L., welted thistle, and C. nutans L., nodding thistle (Composite);Harris,1971