1. Adams, R. P., andB. L. Turner. 1970. Chemosystematics and numerical studies of natural populations ofJuniperus ashei Buch. Taxon 19:728–751.
2. Ballentine, K. D., andA. E. Schwarting. 1949.Mentha cardiaca. I. Pharmacognostical studies and a preliminary investigation of the volatile oil. J. Amer. Pharm. Assoc., Sci. Ed. 38:241–243.
3. Baquar, S. R. 1967. Pharmacognostic studies onMentha spicata L. in relationship to two of its hybridsM. piperita L. andM. gentilis L. Pakistan J. Sci. Industr. Res. 10:137–139.
4. —, andG. Reese. 1965. Cytotaxonomische und gaschromatographische Untersuchungen an norddeutschenMentha-Formen. 2. Teil Gaschromatographische Untersuchungen. Pharmazie Beih. Ergänzungsband 20:214–220.
5. Chopra, M. M., V. N. Vahist, andK. L. Handa. 1964. The essential oils of the species of genusMentha. Perfumery & Essential Oil Rec. 55:323–329.