Ratnaike, R. N., J. E. Buttery and Sheryl Hoffmann. "Blood Ammonia Measurement Using a Simple Reflectometer" Clinical Chemistry and Laboratory Medicine, 22.1 (2009): 105-108. Retrieved 25 May. 2013, from doi:10.1515/cclm.1984.22.1.105

Ratnaike, R., Buttery, J. & Hoffmann, S. (2009). Blood Ammonia Measurement Using a Simple Reflectometer. Clinical Chemistry and Laboratory Medicine, 22(1), pp. 1-128. Retrieved 25 May. 2013, from doi:10.1515/cclm.1984.22.1.105

Ratnaike, R. N., J. E. Buttery and Sheryl Hoffmann. 2009. Blood Ammonia Measurement Using a Simple Reflectometer. Clinical Chemistry and Laboratory Medicine. 22(1): 1-128. Retrieved 25 May. 2013, from doi:10.1515/cclm.1984.22.1.105