Published: 2019-10-04

DOI: https://doi.org/10.31580/jpvai.v2i3.927
DOI: https://doi.org/10.31580/jpvai.v2i3.899
DOI: https://doi.org/10.31580/jpvai.v2i3.921
DOI: https://doi.org/10.31580/jpvai.v2i3.930