H. Schaefer

Analysis of the factors influencing energy consumption in industry: A revised method

Manfred Rudolph, Walter Reitler, Manfred Rudolph, 1987 .

Energy life cycle analysis of hydrogen systems

B. Geiger, U. Wagner, U. Wagner, 1998 .

Hidden energy and correlated environmental characteristics of P.V. power generation

Helmut Schaefer, Gerd Hagedorn, H. Schaefer, 1992 .