Sách điện tử

1.   Earth As Art by Lawrence Friedl, et al. - NASA , 2012
This book celebrates Earth's aesthetic beauty in the patterns, shapes, colors, and textures of the land, oceans, ice, and atmosphere. The book features 75 stunning images of Earth from the Terra, Landsat 5, Landsat 7, EO-1, and Aqua satellites.

2. http://www.digitalbookindex.org/subject_search/search010agriculturesoilsa/1

3. http://www.freebookcentre.net/Biology/Soil-Biology-Books.html