APA

Mitchell M., Petzer E. & Walt N. v. d. (1979). Optimum use of natural materials for lightly trafficked roads in developing countries. : Transportation research record.

Chicago

Mitchell MF, Petzer ECP and Walt N van der. 1979. Optimum use of natural materials for lightly trafficked roads in developing countries. : Transportation research record.

Harvard

Mitchell M., Petzer E. and Walt N. v. d. (1979). Optimum use of natural materials for lightly trafficked roads in developing countries. : Transportation research record.

MLA

Mitchell MF, Petzer ECP and Walt N van der. Optimum use of natural materials for lightly trafficked roads in developing countries. : Transportation research record. 1979.