2 1 30 a knowledge management perspective M A Qirom3 Additional Author Y Rochmayanto1* Primary Author N Sakuntaladewi1 Additional Author M Iqbal1 Additional Author D C Hidayat1 Additional Author B Winarno2 Additional Author S Lestari2 Additional Author A Ardhana3 Additional Author L van Kerkhoff4 Additional Author L Robins4 Additional Author mixed material UNITED STATES : IOP Conference Series: Earth and Environmental Science. Vol. 917 Th 2021 2021 W C Adinugroho1* Primary Author H Krisnawati1 Additional Author R Imanuddin1 Additional Author A Syaugi2 Additional Author P B Santosa3 Additional Author M A Qirom3 Additional Author L B Prasetyo4 Additional Author mixed material UNITED STATES IOP Conference Series: Earth and Environmental Science. Vol. 874 Th 2021 2021