Reading extensively to develop reading skill
 Artikel Jurnal
Plattner, Francis B.
Improve your communication and speaking skills
American Society for Training and Development Press, 1997
 eBooks
Isma Kania Muthmainah
Critical soft skill competence manajer proyek pada proyek infrastruktur yang berpengaruh terhadap kinerja biaya = Critical soft skill competence of project manager in infrastructure that affects cost performance
Fakultas Teknik Universitas Indonesia, 2014
 UI - Tesis Membership
Gamble, Teri Kwal
Public speaking
Allyn and Bacon, 1994
 Buku Teks
Briefly speaking: a guide to public speaking in college and career
by Cal M. Lague [and others]
Allyn and Bacon, 1982
 Buku Teks