APA

Burkill G., Giusti L., Maraven, Petróleos de Venezuela P., World Petroleum Congress (11th. : 1983 : London), Giusti L., Maraven & Petróleos de Venezuela P.The Orinoco heavy oil belt. : .

Chicago

Burkill G.C.C, Giusti L.E, Maraven, Petróleos de Venezuela PDVSA, World Petroleum Congress (11th. : 1983 : London), Giusti L.E, Maraven and Petróleos de Venezuela PDVSA.The Orinoco heavy oil belt. : .

Harvard

Burkill G., Giusti L., Maraven, Petróleos de Venezuela P., World Petroleum Congress (11th. : 1983 : London), Giusti L., Maraven and Petróleos de Venezuela P.The Orinoco heavy oil belt. : .

MLA

Burkill G.C.C, Giusti L.E, Maraven, Petróleos de Venezuela PDVSA, World Petroleum Congress (11th. : 1983 : London), Giusti L.E, Maraven and Petróleos de Venezuela PDVSA.: . .