I. G. K. Wulan, A. N. Hidayati, and H. Sukanto, “Profile of Serum Insulin-like Growth Factor-1 Levels in Patients with Acne Vulgaris”, Berkala Ilmu Kesehatan Kulit dan Kelamin (Periodical of Dermatology and Venerology), vol. 28, no. 2, pp. 104–112, Oct. 2016.