Mueller, T., Walter, B., Wirtz, A., & Burkovski, A. (2006). Ammonium toxicity in bacteria. Current Microbiology, 52(5), 400-406. Retrieved from http://springerlink.metapress.com/content/d890599m2217u64h/?p=413302d89d4a40f5a4c3cd5987e75e20&pi=13.