@BOOK{NAP21482, title = "Methane Generation From Human, Animal, and Agricultural Wastes", doi = "10.17226/21482", url = "https://nap.nationalacademies.org/catalog/21482/methane-generation-from-human-animal-and-agricultural-wastes", year = 1977, publisher = "The National Academies Press", address = "Washington, DC" }