APA

Koole R., Valkering C. & Lancon D. (1991). Development of a multigrade bitumen to alleviate permanent deformation. London: Shell Supply and Marketing Publication SM/M/91/120.

Chicago

Koole RC, Valkering CP and Lancon DJL. 1991. Development of a multigrade bitumen to alleviate permanent deformation. London: Shell Supply and Marketing Publication SM/M/91/120.

Harvard

Koole R., Valkering C. and Lancon D. (1991). Development of a multigrade bitumen to alleviate permanent deformation. London: Shell Supply and Marketing Publication SM/M/91/120.

MLA

Koole RC, Valkering CP and Lancon DJL. Development of a multigrade bitumen to alleviate permanent deformation. London: Shell Supply and Marketing Publication SM/M/91/120. 1991.