Regala, R. (1969). World order and diplomacy. Central Lawbook Pub. Co.
Cita Chicago (17th ed.)Regala, Roberto. World Order and Diplomacy. Quezon City: Central Lawbook Pub. Co, 1969.
Cita MLA (9th ed.)Regala, Roberto. World Order and Diplomacy. Central Lawbook Pub. Co, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.