1. Influence of spatial and host plant isolation on polymorphism in Philaenus spumarius;HALKKA;Royal Entomological Society, Symposium,1978
2. Partial population transfers as a means of estimating the effectiveness of natural selection;HALKKA;Heredilas,1974
3. Persistence of visual polymorphism, despite a low rate of predation in Philaenus spumarius (L.) (Homoptera);HALKKA;Annates Zoologici Fennici,1976
4. The genetic basis of balanced polymorphism in Philaenus (Homoptera);HALKKA;Heredilas,1973
5. The founder principle, founder selection, and evolutionary divergence and convergence in natural populations of Philaenus;HALKKA;Heredilas,1974