P. Lereim, N. Langeland, B. Romanus, J. E. Pettersen, and I. F. Goldie, “A Biochemical Analysis of Subchondral Bone of the Medial Tibial Condyle in the Normal State and in Osteoarthritis and Rheumatoid Arthritis”, ActaO, vol. 46, no. 4, pp. 672–684, Jan. 1975.