Librería Samer Atenea
Librería Aciertas (Toledo)
Kálamo Books
Librería Perelló (Valencia)
Librería Elías (Asturias)
Donde los libros
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.