East, Roger
Profiles of people in power: the world's goverment leaders
Routledge, 2006
Buku Referensi
Ople, Blas F.
Profiles in Virtues : a collection of tributes to outstanding Filipino citizens and leaders
Institute for Public Policy, 2001
Buku Teks SO
Making a difference: African-American leaders rap about libraries
Artikel Jurnal
Leaders
Leaders Magazine,
Majalah, Jurnal, Buletin
Nixon, Richard
Leaders
Warner Books, 1982
Buku Teks SO