Kohona, Palitha T.B., author
Martinus Nijhoff, 1985
Buku Teks
Louis Meuleman, editor
[Springer, ], 2013
eBooks
Pippa Norris, Richard W. Frank, and Ferran MartÃnez i Coma.
Oxford University Press , 2014
Buku Teks
Jackson, John H., author
West Publishing, 2013
Buku Teks
Mohrman, Susan Albers, author
Berrett-Koehler, 2011
Buku Teks