Sinaga, Martha
Habit Profesional
Gramedia, 2006
 Buku Teks
Covey, Stephen R.
The 8th habit : melampaui efektivitas, menggapai keagungan = The 8th habit
Gramedia, 2005
 Buku Teks
Covey, Stephen R.
The 8th habit : from effectiveness to greatness
Free Press, 2004
 Buku Teks
Durkheim, Emile
Journal sociologique
Presses Universitaires De France , 1969
 Buku Teks
Journal of Population
The Demographic Institue FE-UI, 1995
 Majalah, Jurnal, Buletin