Xiao-Ru Wang, Yoshihiko Tsumura, Hiroshi Yoshimaru, Kazutoshi Nagasaka and Alfred E. Szmidt. 1999. Phylogenetic relationships of Eurasian pines (Pinus, Pinaceae) based on chloroplast rbcL, MATK, RPL20-RPS18 spacer, and TRNV intron sequences. American Journal of Botany 86: 1742-1753. Available http://www.amjbot.org/cgi/content/full/86/12/1742, accessed 2006.11.19.