APA 6th Edition Principe, A.D. (1999). Kolonijalna utopija. Prostor, 7 (2(18)), 143-156. Preuzeto s https://hrcak.srce.hr/24015
MLA 8th Edition Principe, Alberto Darias. "Kolonijalna utopija." Prostor, vol. 7, br. 2(18), 1999, str. 143-156. https://hrcak.srce.hr/24015. Citirano 15.06.2021.
Chicago 17th Edition Principe, Alberto Darias. "Kolonijalna utopija." Prostor 7, br. 2(18) (1999): 143-156. https://hrcak.srce.hr/24015
Harvard Principe, A.D. (1999). 'Kolonijalna utopija', Prostor, 7(2(18)), str. 143-156. Preuzeto s: https://hrcak.srce.hr/24015 (Datum pristupa: 15.06.2021.)
Vancouver Principe AD. Kolonijalna utopija. Prostor [Internet]. 1999 [pristupljeno 15.06.2021.];7(2(18)):143-156. Dostupno na: https://hrcak.srce.hr/24015
IEEE A.D. Principe, "Kolonijalna utopija", Prostor, vol.7, br. 2(18), str. 143-156, 1999. [Online]. Dostupno na: https://hrcak.srce.hr/24015. [Citirano: 15.06.2021.]
Sažetak The idea of a Gibraltar tunnel first appeared in the mid XIX century, with the first technical developments that led people to think, with excessive optimism, that the project was possible. It was not until several attempts had failed, that a military engineer appeared in the 30's with the conviction that a task of this magnitude was feasible. He cautiously took the first steps and initiated the necessary studies, and even made the first surveys. But, the Spanish Civil War and the Second World War interrupted what had been a promising start. When the idea was taken up again, it coincided with Moroccan independence and had to be discarded until very recently.