http://www.issia.cnr.it/ http://www.ba.iac.cnr.it/wp/ https://ntnucamp.sce.ntnu.edu.tw/ http://leda.elfak.ni.ac.rs/

Gaya APA

Drucker, P, F. (2002). Effective Executive, The : The Definitive Guide to getting the right things done . New York, USA: Harper Business Essentials.

Gaya MLA

Drucker, Peter, F.. "Effective Executive, The : The Definitive Guide to getting the right things done". New York, USA: Harper Business Essentials, 2002. Academic.