Sari, Dwi Novita, and Syukrul Hamdi. 2021. “Is Online Learning Effective Implemented in the Outbreak of Covid-19? (An Evaluation Approach in the Vocational High Schools)”. Jurnal Pendidikan Teknologi Dan Kejuruan 27 (2):117-25. https://doi.org/10.21831/jptk.v27i2.36107.