Vinda Regita Cahyani and Slamet Sujud Purnawan Jati, “Development of Teaching Materials E-booklet based on Flip PDF Professional on Technological Development in The Period of Perundagian in Indonesia for Students Class X SMK : Pengembangan Bahan Ajar E-booklet berbasis Flip PDF Professional Materi Perkembangan Teknologi pada Masa Perundagian di Indonesia untuk Siswa Kelas X SMK”, JS, vol. 7, no. 1, pp. 215-225, Jun. 2023.