Heinonen-Tanski, H., Simojoki, P., Raininko, K., Nuormala, N. and Silvo, R. 1989. Effect of annual use of pesticides on soil microorganisms and sugar beet yields. Agricultural and Food Science. 61, 1 (Jan. 1989), 45–53. DOI:https://doi.org/10.23986/afsci.72351.