| ANETHOLE |
Martindale's 29th |
| CAMPHOR |
Martindale's 29th |
| GERANIOL |
Madaus, G. 1976. Lehrbuch der Biologischen Hilfmittel. Vol,. 1-3. 2862 pp. (+ 144 p. index). Georg Olms Verlag, Hildescheim. Reprint of 1938 Madaus. |
| MENTHOL |
Yamamoto, A., Umemori, S., and Muranishi, S. 1993. Absorption Enhancement of Intrapulmonary Administered Insulin by Various Absorption Enhancers and Protease Inhibitors in Rats. J. Pharm. Pharmacol. 46: 14-18, 1994. |
| THYMOL |
Leung, A. Y. and Foster, S. 1995. Encyclopedia of Common Natural Ingredients 2nd Ed. John Wiley & Sons, New York. 649 pp. |