"Manure gases." . . "Manure gases" . "Biogas." . . "Gas manufacture and works" . . "Gas manufacture and works Handbooks, manuals, etc." . . "Énergie de la biomasse." . . "Apparatuur." . . "Déchets agricoles Recyclage." . . "Zelfbouw." . . "Biomasse Recherche." . . "Fumier." . . "Gazogènes." . . . . "Méthane." . . "Methane." . "Methane" . "Biogaz." . . "Fermentation." . . . . . . . . . . . . "Practical building of methane power plants : for rural energy indepenence : [dungas systems]" . "Handbooks, manuals, etc" . "Practical building of methane power plants for rural energy independence" . "Practical building of methane power plants for rural energy independence"@en . . . . . . . . . "Practical building of methane power plants for rural energy independance" . . . . "Practical Building of Methane Power Plants for Rural Energy Independence"@en . . . . . . . . . . . . . . . . "Handbooks and manuals" . . . . . . . . . . . . . . . . . .