http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Estimation of rumen microbial protein production from purine derivatives in urine
"A laboratory manual for the FAO/IAEA Co-ordinated research programme on development, standardization and validation of nuclear based technologies for measuring microbial protein supply in ruminant livestock for improving productivity"