APA

Shell International Petroleum Comp, . (1977). Stiffness of bitumen and bituminous mixes. London: Shell International Petroleum Comp., Customer publ. nr 29/77.

Chicago

Shell International Petroleum Comp, . 1977. Stiffness of bitumen and bituminous mixes. London: Shell International Petroleum Comp., Customer publ. nr 29/77.

Harvard

Shell International Petroleum Comp, . (1977). Stiffness of bitumen and bituminous mixes. London: Shell International Petroleum Comp., Customer publ. nr 29/77.

MLA

Shell International Petroleum Comp, . Stiffness of bitumen and bituminous mixes. London: Shell International Petroleum Comp., Customer publ. nr 29/77. 1977.