Wojakowska, A., Krzyżak, E. and Plińska, S. (2007): "Melting and high-temperature solid state transitions in cobalt(II) halides". Journal of Thermal Analysis and Calorimetry, volume 88, issue 2, pages 525-530. doi:10.1007/s10973-006-8000-9
M. T. Saugier, M. Noailly, R. Cohen-Adad, F. Paulik, and J. Paulik (1977): "Equilibres solide ⇄ liquide ⇆ vapeur du systeme binaire CoCl 2-H 2O" Journal of Thermal Analysis, volume 11, issue 1, pages 87–100. doi:10.1007/BF02104087 Note: the lowest point of fig.6 is inconsistent with fig.7; probably should be at -27.8 C instead of 0 C.