International Protea Research Symposium San Diego, Calif, International Society for Horticultural Science. Protea Working Group, International Society for Horticultural Science. Section for Ornamental Plants, Criley, R. A., & Parvin, P. E. (1990). Second International Protea Research Symposium: San Diego, California, U.S.A., March 7-8, 1989. International Society for Horticultural Science.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)International Protea Research Symposium San Diego, Calif, International Society for Horticultural Science. Protea Working Group, International Society for Horticultural Science. Section for Ornamental Plants, Richard A. Criley, و Philip Eugene Parvin. Second International Protea Research Symposium: San Diego, California, U.S.A., March 7-8, 1989. Wageningen, Netherlands: International Society for Horticultural Science, 1990.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)International Protea Research Symposium San Diego, Calif, et al. Second International Protea Research Symposium: San Diego, California, U.S.A., March 7-8, 1989. International Society for Horticultural Science, 1990.