M. Lind, S. Overgaard, T. Nguyen, B. Ongpipattanakul, C. Bunger, and K. Søballe, “Transforming growth factor-6 stimulates bone ongrowth: Hydroxyapatite-coated implants studied in dogs”, ActaO, vol. 67, no. 6, pp. 611–616, Jan. 1996.