Korean Society of welfare for the aged, {s.a}
Majalah, Jurnal, Buletin
University of Toronto Press, 2018
Majalah, Jurnal, Buletin
Universitas Trilogi, 2014
Majalah, Jurnal, Buletin
Oxford : Pergamon Press Ltd
Majalah, Jurnal, Buletin
Begell House, Inc.,
Majalah, Jurnal, Buletin