JPFA, E. 2019. Introduction, Author Guidelines, and Table of Contents JPFA Vol 9 No 1 June 2019. Jurnal Penelitian Fisika dan Aplikasinya (JPFA). 9, 1 (Jun. 2019), ii-vi. DOI:https://doi.org/10.26740/jpfa.v9n1.pii-vi.