APA
Aguilera R., Cordell G., Nicholl G. W., Cordell G. & Nicholl G. W. (1991). Horizontal wells. Houston: Gulf Publishing.
Chicago
Aguilera Roberto, Cordell G.M, Nicholl G W, Cordell G.M and Nicholl G W. 1991. Horizontal wells. Houston: Gulf Publishing.
Harvard
Aguilera R., Cordell G., Nicholl G. W., Cordell G. and Nicholl G. W. (1991). Horizontal wells. Houston: Gulf Publishing.
MLA
Aguilera Roberto, Cordell G.M, Nicholl G W, Cordell G.M and Nicholl G W. Horizontal wells. Houston: Gulf Publishing. 1991.