Librería Samer Atenea
Kálamo Books
Librería Elías (Asturias)
Librería Kolima (Madrid)
Librería Proteo (Málaga)
Uses diagrams and pictures to show how the basic design of the biogas pit can be adapted for construction in different soils, from sandstone to sheer rock, which should encourage other developing countries to embark on their own biogas programmes.