1. Assoc. of Official Agr. Chem., 1940. Methods of Analysis, 5th Edition, p. 371-372.
2. Biological Assay of Vitamin D3.I;Baker;Assay methods at present in use, with particular reference to Olsson's radiographic technic. Analyst,1940
3. Biological assay;Bliss;Ann. Rev. Physiol.,1943
4. British Standard Method for the Biological Assay of Vitamin D3 by the Chick Method;British Standards Institution;Specification No.,1940
5. Campbell, J. A., B. B. Migicovsky and A. R. G. Emslie, 1944. Studies on the chick assay for vitamin D. I. Precision of tibia and toe ash as criteria of response. Poultry Sci. (in press).