Gaya APA

Dowling, J. W. F.. (1982). Natural asphalts: their occurance, properties and use in road construction in Columbia . : TRRL.

Gaya Chicago

Dowling, J. W. F.. Natural asphalts: their occurance, properties and use in road construction in Columbia. : TRRL, 1982. Chart.

Gaya MLA

Dowling, J. W. F.. Natural asphalts: their occurance, properties and use in road construction in Columbia. : TRRL, 1982. Chart.

Gaya Turabian

Dowling, J. W. F.. Natural asphalts: their occurance, properties and use in road construction in Columbia. : TRRL, 1982. Chart.