Fresenius' Zeitschrift fuer Analytische Chemie, , vol. 2, p. 33 Justus Liebigs Annalen der Chemie, , vol. 137, p. 288 Journal of Biological Chemistry, , vol. 21, p. 583 Journal of Biological Chemistry, , vol. 59, p. 347 Journal of Biological Chemistry, , vol. 48, p. 133 Journal of Biological Chemistry, , vol. 53, p. 323