2 1 10 Ir. Ch.Hutauruk Additional Author Ir. A.U.Lubis Additional Author Ir. E.L.Tobing Additional Author Ir. A.Sipayung Additional Author Ir. Soedharto Ps. Additional Author Ir. Suheimi Syukur Additional Author Ir. P.Purba Additional Author mixed material Pematang Siantar Pusat Penelitian Marihat 1982 COVER_VOL.3_No.2.jpg Ir. H. Adlin U. Lubis Additional Author Ir. Fidber Chan Additional Author Ir. E. Manalu Additional Author Ir. Kiki Siregar Additional Author Ir. P. Purba Additional Author Ir. H.S. Situmorang Additional Author mixed material 02161427 Pematang Siantar Pusat Penelitian Marihat 1987