Prayitno, T. B. “TEORI GAUGE DAN GRUP SIMETRI INTERNAL”. PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL), Vol. 1, no. 1, Oct. 2012, pp. 25 -31, https://journal.unj.ac.id/unj/index.php/prosidingsnf/article/view/6146.