Shamsudin, N. H., and Zulkurnain Bin Hassan. “KEBERKESANAN TRAINER UNIT SPPD SEBAGAI ALAT BANTU MENGAJAR BAGI KURSUS PEMASANGAN DAN PENYELENGGARAAN PAIP DOMESTIK: The Effectiveness of Sppd Unit Trainers As Teaching Aids for Domestic Pipe Installation and Maintenance Courses”. International Journal of Humanities Technology and Civilization, vol. 6, no. (S2), Mar. 2021, pp. 29-36, doi:10.15282/ijhtc.v6i(S2).6247.