Riso, Don Richard
Discovering Your Personality Type: the new enneagram questionnaire / Don Richard Riso
Houghton Miffiln, 1995
 Buku Teks
Don Richard Riso
Understanding the enneagram the practical guide to personality types/ Don Richard Riso, Russ Hudson
Houghton Mifflin, 2000
 Buku Teks
Mary, Leena
Searching speech databases: Features, techniques and evaluation measures
Springer Cham, 2019
 eBooks
Crane, Rebecca, 1964-
Mindfulness-based cognitive therapy: distinctive features
Routledge, Taylor & Francis Group, 2017
 Buku Teks
Dian Kurniasih Wahyu Sari
Penggunaan metode diskusi kelompok berdasarkan tipe kepribadian dan kemahiran berbicara dalam pengajaran kemahiran berbicara = The use of group discussion based on personality type and student speaking skills in teaching speaking
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2018
 UI - Tesis Membership