Kurppa, S. and Suonpää, M. 1990. Infestations and distribution of Rhopalosiphum padi (L.) on different varieties of barley and oats, effect of nitrogen fertilization and chemical control. Agricultural and Food Science. 62, 1 (Jan. 1990), 33–44. DOI:https://doi.org/10.23986/afsci.72922.