Michael Beman, J., Popp, B. N., & Alford, S. E. (2012). Quantification of ammonia oxidation rates and ammonia-oxidizing archaea and bacteria at high resolution in the Gulf of California and eastern tropical North Pacific Ocean. Limnology and Oceanography, 57(3), 711–726. doi:10.4319/lo.2012.57.3.0711