APA-referens (7:e uppl.)

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

Chicago-referens (17:e uppl.)

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.

MLA-referens (8:e uppl.)

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