Levine, Karen
Vermont Storey Books, 1996
Buku Teks
DeVillers, Julia, author
Prima Pub, 2002
Buku Teks
Hubbard, L. Ron, 1911-1986, author
The Way to Happiness Foundation International, 2007
Buku Teks
Fitri Fujiana, author
2015
UI - Tesis (Membership)
Dela Raskyandra, author
2018
UI - Skripsi (Membership)