Wright, Craig M., author
Schirmer Cengage Learning, 2013
Buku Teks
Downs, Lisa J., author
American Society for Training & Development, 2008
eBooks
Burley-Allan, Madelyn, author
John Wiley & Sons, 1982
Buku Teks
Dwi Wahyuningsih, author
Kantor Bahasa Banten, 2018
Artikel Jurnal
Cunningham, Sarah, author
Oxford University Press , 1994
Buku Teks