Cosmo G. Mackenzie, Joseph P. Chandler, Elizabeth B. Keller, Julian R. Rachele, Nancy. Cross, Vincent. du Vigneaud,
The oxidation and distribution of the methyl group administered as methionine. Journal of Biological Chemistry. ,vol. 180, pp. 99- 111 ,(1949) ,
10.1016/S0021-9258(18)56727-2