Trask, R.L.
Key concepts in language and linguistics
London, 1998
 Buku Referensi
Key thinkers in linguistics and the philosophy of language
edited by Siobhan Chapman
Oxford University Press, 2005
 Buku Teks
Key Thinkers in linguistics and the Philosophy of language
Edinburgh, Edinburgh University Press, 2005
 Buku Referensi
Vernon, Mark
Bisnis: the key concepts = Business: the key concepts
RajaGrafindo Persada, 2011
 Buku Teks
Cultural Theory the key concepts
edited by Andrew Edgar and Peter Sedgwick
Routledge , 2006
 Buku Teks