Gray, P. S. and J. S. Mills. "Isolation of abienol from Canada balsam, the oleoresin of Abies balsamea (L.) Mill." Journal of the Chemical Society (1964): 5822-5825.

Gray, P. S. and J. S. Mills. "Isolation of abienol from Canada balsam, the oleoresin of Abies balsamea (L.) Mill." Journal of the Chemical Society (1964): 5822-5825.