by K. Usman & L.K. Ara $5.00
by Prof. Dr. Suharsimi Arikunto $11.00
by Prof. Subowo, dr. M.Sc., Ph.D $7.00
by Drs. Abas Kartadinata $7.00
by Prof. Dr. S. Nasution, M.A. $7.00
by Murad Lesmana, Jeanette $5.00