An annotated bibliography of the foundational works behind today's Sustainable and Organic Agriculture movement, put together by the US Department of Agriculture's National Agricultural Library.
A thorough and scholarly historical survey of the development of naturopathic and nature cure practices from the 19th through the 20th century. A study of the individuals who made it happen. For many years Kirchfeld was librarian at the National College of Naturopathic Medicine.
Dr. Alan Immerman collected every available scrap of published scientific evidence issued between 1880 and 1980 that supported Natural Hygiene/Nature Cure. This material (a seven foot tall stack of photocopies) was then scanned by Dr. Immerman. All these articles are available for free download, organized by topic.