An amazing resource for obscure and out-of-print documents on soil, agriculture, and health.  Most of the documents are free e-books, mainly about holistic agriculture, holistic health and self-sufficient homestead living.  There are four major subject areas including an extensive selection of rare books on radical agriculture that goes beyond organic gardening and farming.

http://www.soilandhealth.org/01aglibrary/01aglibwelcome.html