Classic texts: Thomas 1907.
Henriette's herbal blog: Good for respiratory problems, and good as a herbal oil, too.
Classic texts: Eli Jones' Definite Medication, 1911.
Classic texts: Ellingwood 1910.
Archives: Best of the Herbal Forums: 10.1995.
Henriette's herbal blog: If you get lung grunges every year you need to strengthen your lungs.
Henriette's herbal is one of the oldest and largest herbal medicine sites on the net. It's been online since 1995, and is run by Henriette Kress, a herbalist in Helsinki, Finland.
Plant Healer Magazine: Very relevant to the practitioner.
http://www.henriettes-herb.com - Copyright 1995–2015 Henriette Kress.