Mustafa Emre CİVELEK, Murat ÇEMBERCİ, Fatma Serab ONURSAL, Mustafa Emre CİVELEK, Nagehan UCA and Okşan KİBRİTCİ ARTAR 2017. ANALYSIS OF BUSINESS POSITIONS REQUIRING PROFESSIONAL COMPETENCE CERTIFICATES IN CIVIL AVIATION. International Journal of Eurasia Social Sciences . 8, 27 (Jun. 2017), 680–712.