Kowalchuk, G. A., Naoumenko, Z. S., Derikx, P. J. L., Felske, A., Stephen, J. R., & Arkhipchenko, I. A. (1999). Molecular Analysis of Ammonia-Oxidizing Bacteria of the β Subdivision of the Class Proteobacteria in Compost and Composted Materials. American Society for Microbiology.

Kowalchuk, George A., Zinaida S. Naoumenko, Piet J. L. Derikx, Andreas Felske, John R. Stephen, and Irina A. Arkhipchenko. Molecular Analysis of Ammonia-Oxidizing Bacteria of the β Subdivision of the Class Proteobacteria in Compost and Composted Materials. American Society for Microbiology, 1999.

Kowalchuk, George A., et al. Molecular Analysis of Ammonia-Oxidizing Bacteria of the β Subdivision of the Class Proteobacteria in Compost and Composted Materials. American Society for Microbiology, 1999.