Allbright, 1931. United State Patent Office, patent number: 1791439 Document reference Allbright, W. B., 1931. Semi-continuous dry-rendering and meal-manufacturing process. United State Patent Office, patent number: 1791439Web http://www.google.fr/patents?id=q9lAAAAAEBAJCitation key Allbright, 1931Datasheets Poultry by-product meal
