Cita APA (7th ed.)

Philippines (Republic). Office of the President. Presidential Economic Staff. (1967). Provincial profiles: Ilocos Sur. PES.

Cita Chicago (17th ed.)

Philippines (Republic). Office of the President. Presidential Economic Staff. Provincial Profiles: Ilocos Sur. Manila: PES, 1967.

Cita MLA (9th ed.)

Philippines (Republic). Office of the President. Presidential Economic Staff. Provincial Profiles: Ilocos Sur. PES, 1967.