Daniel Ganda Putra Sihombing, David Togi Hutahaean, Yanti kristina Sinaga, Tiarma Intan Marpaung, and Anita Sitanggang. “The Effect Of Reinforcement On Writing Skill At Eleventh Grade Students In SMK Negeri 1 Pematang Siantar ”. Jurnal Ilmu Pendidikan dan Sosial 2, no. 3 (October 31, 2023): 381–389. Accessed April 27, 2026. https://www.putrapublisher.org/index.php/jipsi/article/view/447.