[Heating systems in the modernization of old buildings].
D003031:Coal; D004560:Electricity; D005648:Fuel Oils; D005740:Gases; D005860:Germany, West; D006361:Heating; D006798:Housing
D003031:Coal; D005648:Fuel Oils; D005740:Gases
Heizungssysteme für Altbaumodernisierung