Não informado. (1976). Erda energy research abstracts. Energy Research and Development Administration.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Erda Energy Research Abstracts. Washington: Energy Research and Development Administration, 1976.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Erda Energy Research Abstracts. Energy Research and Development Administration, 1976.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.