@article{Alt1992, author = {Alt, Helmut}, title = {M{\"o}glichkeiten der CO2-Minderung "alternativ" betrachtet}, series = {Etz : Elektrotechnik \& Automation}, volume = {Bd. 113}, journal = {Etz : Elektrotechnik \& Automation}, number = {H. 6-7}, issn = {0170-1711}, pages = {400}, year = {1992}, language = {de} } @article{Alt1992, author = {Alt, Helmut}, title = {Renditevergleich zwischen Immobilien und Festverzinslichen}, series = {Die Bank}, journal = {Die Bank}, number = {H. 2}, issn = {0342-3182}, pages = {91 -- 92}, year = {1992}, language = {de} }