APA

Hopkins J., Newfell A., . (1975). Guidelines for enhancement of visual conspicuity for trains at grade crossings. Cambridge, MA: U.S. Department of Transportation. Transportation Systems Center. Report nr 74-15.

Chicago

Hopkins JB, Newfell AT, . 1975. Guidelines for enhancement of visual conspicuity for trains at grade crossings. Cambridge, MA: U.S. Department of Transportation. Transportation Systems Center. Report nr 74-15.

Harvard

Hopkins J., Newfell A., . (1975). Guidelines for enhancement of visual conspicuity for trains at grade crossings. Cambridge, MA: U.S. Department of Transportation. Transportation Systems Center. Report nr 74-15.

MLA

Hopkins JB, Newfell AT, . Guidelines for enhancement of visual conspicuity for trains at grade crossings. Cambridge, MA: U.S. Department of Transportation. Transportation Systems Center. Report nr 74-15. 1975.