Romagnoli, C. ., Zonefrati, R. ., Galli, G. ., Aldinucci, A. ., Nuti, N. ., Martelli, F. ., … Brandi, M. . (1969). The effect of strontium chloride on human periodontal ligament stem cells. Clinical Cases in Mineral and Bone Metabolism : The Official Journal of the Italian Society of Osteoporosis, Mineral Metabolism, and Skeletal Diseases, 14(3), 283-293. https://doi.org/10.11138/ccmbm/2017.14.3.283 (Original work published 1969)