Proceedings of the twentieth annual convention : Jakarta 8th - 10th October 1991 Proceeding of the eleventh annual convention, Jakarta, June 8-9, 1982 Proceeding of the eleventh annual convention, Jakarta, June 7-8, 1983 Proceedings of the fourteenth annual convention Jakarta 8-10, 1985 Proceedings of the eleventh annual convention, Jakarta, June 8-9 1992 Proceedings of the eleventh annual convention, Jakarta, June 8-9 1992Proceedings of the fifth annual convention, Jakarta, June 7- 8 1976Proceedings of the third annual convention, Jakarta, June 3-4 1974Proceedings of the fourth annual convention, Jakarta, June 2-3 1975Proceedings of the twelfth annual convention, Jakarta, June 8-10 1985