Browsing PhD in Economics, Administration and Computer Science by Author "%CE%A7%CE%B1%CF%81%CE%B1%CE%BB%CE%AC%CE%BC%CF%80%CE%BF%CF%85%CF%82%2C %CE%9A%CF%89%CE%BD%CF%83%CF%84%CE%B1%CE%BD%CF%84%CE%AF%CE%B1"