Siniscalchi, Carmine, et al. “Hypoglicemia Related to Big Haemangiopericitoma: A Difficult Diagnostic Definition”. Acta Biomedica Atenei Parmensis, vol. 86, no. 2, Sept. 2015, pp. 189-92, https://www.mattioli1885journals.com/index.php/actabiomedica/article/view/4162.