APA
POPULATION REFERENCE BUREAU, . (2006). THE WORLD'S YOUTH. WASHINGTON D.C. USA: POPULATION REFERENCE BUREAU.
Chicago
POPULATION REFERENCE BUREAU, . 2006. THE WORLD'S YOUTH. WASHINGTON D.C. USA: POPULATION REFERENCE BUREAU.
Harvard
POPULATION REFERENCE BUREAU, . (2006). THE WORLD'S YOUTH. WASHINGTON D.C. USA: POPULATION REFERENCE BUREAU.
MLA
POPULATION REFERENCE BUREAU, . THE WORLD'S YOUTH. WASHINGTON D.C. USA: POPULATION REFERENCE BUREAU. 2006.
