APA

Sanford J., . (1977). Criteria used by state highway agencies to determine warrants and priorities for warning devices at rail-highway crossings. Urbana, IL: Illinois University. Highway Traffic Safety Center. RR nr 8.

Chicago

Sanford JL, . 1977. Criteria used by state highway agencies to determine warrants and priorities for warning devices at rail-highway crossings. Urbana, IL: Illinois University. Highway Traffic Safety Center. RR nr 8.

Harvard

Sanford J., . (1977). Criteria used by state highway agencies to determine warrants and priorities for warning devices at rail-highway crossings. Urbana, IL: Illinois University. Highway Traffic Safety Center. RR nr 8.

MLA

Sanford JL, . Criteria used by state highway agencies to determine warrants and priorities for warning devices at rail-highway crossings. Urbana, IL: Illinois University. Highway Traffic Safety Center. RR nr 8. 1977.