Παραπομπή σε μορφή APA (7η εκδ.)

Roos, G. (1935). Comparative researches on the variation of the constituents of coal of one seam from south Limburg: The Netherlands. Van Aelst Bros.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Roos, Gerrit. Comparative Researches on the Variation of the Constituents of Coal of One Seam from South Limburg: The Netherlands. Maastricht: Van Aelst Bros, 1935.

Παραπομπή σε μορφή MLA (8th εκδ.)

Roos, Gerrit. Comparative Researches on the Variation of the Constituents of Coal of One Seam from South Limburg: The Netherlands. Van Aelst Bros, 1935.