Pengaruh kohesifitas kelompok (group cohesiveness) dan motivasi terhadap kinerja (job performance) : studi pada Biro Kepegawaian Kementerian A = The effect of group cohesiveness and motivation toward job performance : studies in Staffing Agency of Ministry A / Rachmat Kurniawan Ratdityas - Rachmat Kurniawan Ratdityas, author (Fakultas Psikologi Universitas Indonesia, 2013)