Azizah, U., Djono, D. and Musadad, A.A. 2020. Developing Digital Book Based on Lafran Pane’ Thought for Increasing State Defend Attitude of Students. Yupa: Historical Studies Journal. 4, 1 (Sep. 2020), 29-39. DOI:https://doi.org/10.30872/yupa.v4i1.235.