APA-referens (7:e uppl.)

Helcke, G. (1981). The energy saving guide: Tables for assessing the profitability of energy saving measures with explanatory notes and worked examples (First edition.). Pergamon Press. https://doi.org/10.1016/C2013-0-03476-7

Chicago-referens (17:e uppl.)

Helcke, George. The Energy Saving Guide: Tables for Assessing the Profitability of Energy Saving Measures with Explanatory Notes and Worked Examples. First edition. Oxford: Pergamon Press, 1981. https://doi.org/10.1016/C2013-0-03476-7.

MLA-referens (9:e uppl.)

Helcke, George. The Energy Saving Guide: Tables for Assessing the Profitability of Energy Saving Measures with Explanatory Notes and Worked Examples. First edition. Pergamon Press, 1981. https://doi.org/10.1016/C2013-0-03476-7.