APA

Repsol-Harvard Seminar (10mo. : 1999 jun. : Madrid), . (1999). Preparing for the twenty-first century. Madrid: William W. Hogan.

Chicago

Repsol-Harvard Seminar (10mo. : 1999 jun. : Madrid), . 1999. Preparing for the twenty-first century. Madrid: William W. Hogan.

Harvard

Repsol-Harvard Seminar (10mo. : 1999 jun. : Madrid), . (1999). Preparing for the twenty-first century. Madrid: William W. Hogan.

MLA

Repsol-Harvard Seminar (10mo. : 1999 jun. : Madrid), . Preparing for the twenty-first century. Madrid: William W. Hogan. 1999.