Gümbel, D. (1993). Principles of holistic therapy with herbal essences (2nd rev. English ed.). Haug International.
芝加哥风格引文Gümbel, Dietrich. Principles of Holistic Therapy with Herbal Essences. 2nd rev. English ed. Brussels: Haug International, 1993.
MLA引文Gümbel, Dietrich. Principles of Holistic Therapy with Herbal Essences. 2nd rev. English ed. Haug International, 1993.
警告：这些引文格式不一定是100％准确.