Laporan PPM K027/2019: Laporan Menghadiri 4th Istanbul International Invention Fair (ISIF'19) Di Istanbul, Turki 17 - 22 September 2019 Dr Rohaya Bt. Othman - Perak Pusat Penyelidikan Mineral, Jabatan Mineral Dan Geosains Malaysia Perak - 14 p ill, col, photo 29 cm