(1999). Personalized system of instruction (PSI)for college algebra. Learning Resource Center.
芝加哥风格引文Personalized System of Instruction (PSI)for College Algebra. Quezon City: Learning Resource Center, 1999.
MLA引文Personalized System of Instruction (PSI)for College Algebra. Learning Resource Center, 1999.
警告：这些引文格式不一定是100％准确.