Mortier, A., Lemaitre, J., & Rouxhet, P. (1987). Formation of Beta-tricalcium Di(orthophosphate) From Mixtures of Hydroxyapatite and Calcium Hydrogen Ortho-phosphate. Thermochimica Acta, 113, 133-139. https://doi.org/10.1016/0040-6031(87)88316-8 (Original work published 1987)