1. Some studies in the U.S.A;Ambrose;Fishing News Int.,1964
2. Association of Official Agricultural Chemists, 1975. Official methods of analysis. 12th ed. Washington, DC.
3. Some South African studies;Dreosti;Fishing News Int.,1964
4. A comparison of six protein quality assays using commercially available protein meals;Johnston;Poultry Sci.,1979
5. Die Bestimmung der verdauliehkeit des rohproteins ouf künstlichem wege;Kastell;Bodendultur,1961