Zhelev, C. Customer Relationship Management - Basic Understandings and Contemporary Issues. Sofia: UNWE Publishing Complex, 2020 94-106,.
Zhelev, C. Customer Relationship Management - Basic Understandings and Contemporary Issues. Sofia: UNWE Publishing Complex, 2020 94-106,.
Zhelev, C. (2020) Customer Relationship Management - Basic Understandings and Contemporary Issues, Sofia: UNWE Publishing Complex 94-106,.
Zhelev, C. (2020). Customer Relationship Management - Basic Understandings and Contemporary Issues. Quality Management and Competitiveness of Bulgarian and Japanese Small and Medium Enterprises (с. 94-106). Sofia: UNWE Publishing Complex.
Zhelev C. Customer Relationship Management - Basic Understandings and Contemporary Issues. Sofia: UNWE Publishing Complex; 2020. p. 94-106.