S. S. SASTROUTOMO, A. S. JURAIMI, J. KADIR, S. NAPIS, and A. TASRIF, “MORPHOLOGICAL VARIATION OF THE ECOTYPES OF Echinochloa crus-galli var crus-galli (L). Beauv (Barnyard grass: Poaceae) IN MALAYSIA and INDONESIA”, BIOTROPIA, no. 22, Nov. 2011.