Hill, Stuart.
Exploring and Appreciating the World under Our Feet. - Minnesota-U.S : International Alliance for Sustainable Agriculture. - p. 4 - Irregular - Vol. 9, no. 1 (1992) - Manna ; no. 1 . - In the Newman Center at the University of Minnesota. .
Exploring and Appreciating the World under Our Feet. - Minnesota-U.S : International Alliance for Sustainable Agriculture. - p. 4 - Irregular - Vol. 9, no. 1 (1992) - Manna ; no. 1 . - In the Newman Center at the University of Minnesota. .
