APA

Richards S. H., Margiotta R. & Evans G. (1991). Warning time requirements at railroad-highway grade crossings with active traffic control. Final report. Washington DC: U.S. Department of Transportation.

Chicago

Richards Stephen H, Margiotta RA and Evans GA. 1991. Warning time requirements at railroad-highway grade crossings with active traffic control. Final report. Washington DC: U.S. Department of Transportation.

Harvard

Richards S. H., Margiotta R. and Evans G. (1991). Warning time requirements at railroad-highway grade crossings with active traffic control. Final report. Washington DC: U.S. Department of Transportation.

MLA

Richards Stephen H, Margiotta RA and Evans GA. Warning time requirements at railroad-highway grade crossings with active traffic control. Final report. Washington DC: U.S. Department of Transportation. 1991.