1. Investigations on Sphenoptera (Chilostetha) jugoslavica Obeb. (Col. Bupresitidea), a possible biocontrol agent of the weed Centaurea diffusa Lam. (Compositae) in Canada. Z. angew;Zwölfer;Entomol.,1976
2. Investigations on Urophora stylata Fabr., a possible agent for the biological control of Cirsium vulgare in Canada;Zwölfer;Prog. Rep. Commonw. Inst. Biol. Control,1972
3. Investigations on the host specificity of Urophora affinis Frfld;Zwölfer;Prog. Rep. Commonw. Inst. Biol. Control,,1970
4. The host-range distribution and life-history of Rhinocyllus conicus Froel;Zwölfer;Prog. Rep. Commonw. Inst. Biol. Control,,1967
5. Preliminary list of phytophagous insects attacking wild cynareae species in Europe;Zwölfer;Tech. Bull. Commonw. Inst. Biol. Control,1965