Metode penelitian kuantitatif, kualitatif dan R & D

Sugiyono  RESEARCH METHODS;

Mixed methode research = metode riset campur sari : konsep, strategi dan aplikasi

Putra, Nusa  RESEARCH METHODS;

Accounting and auditing research and databases : practitioners desk reference

Weirich, Thomas R.  BUSINESS AND ECONOMICS; AUDITING