Citazione Stile APA (7a Edizione)

Ople, B. F. Proposals for further development: Manpower planning ; vocational and career guidance. s.n.].

Citazione stile Chigago Style (17a edizione)

Ople, Blas F. Proposals for Further Development: Manpower Planning ; Vocational and Career Guidance. [S.l: s.n.].

Citatione MLA (9a ed.)

Ople, Blas F. Proposals for Further Development: Manpower Planning ; Vocational and Career Guidance. s.n.].