APA-referens (7:e uppl.)

Oppe, S. (1985). Contribution to evaluation of intermediate variables: Background paper. Institute for Road Safety Research SWOV, The Netherlands.

Chicago-referens (17:e uppl.)

Oppe, Siem. Contribution to Evaluation of Intermediate Variables: Background Paper. Leidschendam: Institute for Road Safety Research SWOV, The Netherlands, 1985.

MLA-referens (9:e uppl.)

Oppe, Siem. Contribution to Evaluation of Intermediate Variables: Background Paper. Institute for Road Safety Research SWOV, The Netherlands, 1985.