Berg, P. (1986). Nitrifier populations and nitrification rates in agricultural soil. Swedish University of Agricultural Sciences, Dept. of Microbiology.
Lua i Stíl Chicago (17ú heag.)Berg, Per. Nitrifier Populations and Nitrification Rates in Agricultural Soil. Uppsala: Swedish University of Agricultural Sciences, Dept. of Microbiology, 1986.
Lua MLA (8ú heag.)Berg, Per. Nitrifier Populations and Nitrification Rates in Agricultural Soil. Swedish University of Agricultural Sciences, Dept. of Microbiology, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.