Kumar, N., N. Garg, and I. Gupta. “Correlation of Intact Parathormone Levels With Serum Calcium, Serum Phosphorus and Serum Vitamin D Levels in Surgical Patients”. Surgical Review: International Journal of Surgery, Trauma and Orthopedics, Vol. 3, no. 4, Dec. 2017, pp. 137-42, doi:10.17511/ijoso.2017.i04.08.