Purba, Resperdiana, and Lisna Evayanti Butar-butar. 2020. “Improving Students’ Achievement on Writing Procedure Text by Using Group Investigation Strategy at SMK Sandhy Putra Medan”. Journal of Maritime and Education (JME) 2 (1):99-102. https://ejournal-poltekamimedan.my.id/index.php/jme/article/view/20.