APA

Colwill D., Butler J. & Crossley P. (1981). Polynuclear aromatic hydrocarbons in the atmosphere in Birmingham. Crowthorne: Transport and Road Research Laboratory. Supplementary report no 656.

Chicago

Colwill DM, Butler JD and Crossley P. 1981. Polynuclear aromatic hydrocarbons in the atmosphere in Birmingham. Crowthorne: Transport and Road Research Laboratory. Supplementary report no 656.

Harvard

Colwill D., Butler J. and Crossley P. (1981). Polynuclear aromatic hydrocarbons in the atmosphere in Birmingham. Crowthorne: Transport and Road Research Laboratory. Supplementary report no 656.

MLA

Colwill DM, Butler JD and Crossley P. Polynuclear aromatic hydrocarbons in the atmosphere in Birmingham. Crowthorne: Transport and Road Research Laboratory. Supplementary report no 656. 1981.