Engler, Dennis. “Hypothesis: Musculin Is a Hormone Secreted by Skeletal Muscle, the body’s Largest Endocrine Organ”. Acta Biomedica Atenei Parmensis, vol. 78, no. 1Suppl, Mar. 2007, pp. 156-0, https://mattioli1885journals.com/index.php/actabiomedica/article/view/4619.