Kymäläinen, H.-R., Kuisma, R., Määttä, J. and Sjöberg, A.-M. 2009. Assessment of cleanness of environmental surfaces in cattle barns and piggeries. Agricultural and Food Science. 18, 3-4 (Jan. 2009), 268–282. DOI:https://doi.org/10.23986/afsci.5955.