University of the Philippines. Open University, Alfonso, G. J., & Reyes, J. C. (2005). Building the problem tree. U.P. Open University.
Chicago Style (17th ed.) CitationUniversity of the Philippines. Open University, Grace Javier Alfonso, and Jaine C. Reyes. Building the Problem Tree. [Quezon City]: U.P. Open University, 2005.
MLA引文University of the Philippines. Open University, et al. Building the Problem Tree. U.P. Open University, 2005.
警告:这些引文格式不一定是100%准确.