Spektra, Editor. “FRONT MATTER SPEKTRA VOLUME 4 ISSUE 2, AUGUST 2019”. Spektra: Jurnal Fisika dan Aplikasinya 4, no. 2 (August 31, 2019). Accessed April 26, 2024. https://journal.unj.ac.id/unj/index.php/spektra/article/view/12321.