Bradbeer, JN., Dunham, J., Fischer, JA., Dedeuxchaisnes, CN., & Loveridge, N. (1988). The Metatarsal Cytochemical Bioassay of Parathyroid-hormone - Validation, Specificity, and Application To the Study of Pseudohypoparathyroidism Type-i. Journal of Clinical Endocrinology and Metabolism, 67(6), 1237-1243. https://doi.org/10.1210/jcem-67-6-1237 (Original work published 1988)