Mápula-Larreta, M.; López-Upton, J.; Vargas-Hernández, J. J.; Hernández-Livera, A. (2007). "Reproductive indicators in natural populations of Douglas-fir in Mexico". Biodiversity and Conservation. 16 (3): 727–742. doi:10.1007/s10531-005-5821-y. S2CID23230135.
Mápula-Larreta, M.; López-Upton, J.; Vargas-Hernández, J. J.; Hernández-Livera, A. (2007). "Reproductive indicators in natural populations of Douglas-fir in Mexico". Biodiversity and Conservation. 16 (3): 727–742. doi:10.1007/s10531-005-5821-y. S2CID23230135.