1. Alecu, C., and Gherasim, O. (2015). Metode şi Tehnici Utilizate în Managementul Organizaţiei, Pro Universitaria.
2. Porter, M. (2008). Despre Concurenţă, Meteor Press.
3. Hill, N. (2007). Customer Satisfaction, Cogent.
4. New Optimization Technique for Sustainable Manufacturing: The Implementation of the Spc Indicator (System of Evaluating Employee Performance Depending on Customer Satisfaction) as an Important Element of Satisfaction Measurement;Legman;Proc. MDPI,2020
5. Augmented Reality technology—A sustainable element for Industry 4.0;Legman;Acta Marisiensis Oecon.,2020