Piantoni, S., L. Andreoli, F. Allegri, P.L. Meroni, and A. Tincani. 2012. “Low Levels of Vitamin D Are Common in Primary Antiphospholipid Syndrome With Thrombotic Disease”. Reumatismo 64 (5), 307-13. https://doi.org/10.4081/reumatismo.2012.307.