[1]
Evans, H.M. and Thomas, W.O. 1983. Y geiriadur mawr: the complete Welsh-English English-Welsh dictionary. Christopher Davies.
[2]
King, G. 1993. Modern Welsh: a comprehensive grammar. Routledge.
[3]
Lewis, D.G. 1996. Y treigladur: a check-list of Welsh mutations. Gomer.
[4]
Meek, E. 2005. Cwrs mynediad: cwrs dechreuol i oedolion sy’n dysgu Cymraeg = a  beginners’ course for adults learning Welsh : pecyn ymarfer = practice pack, Fersiwn y De = South Wales version. Uned Iaith Genedlaethol Cymru, CBAC.
[5]
Meek, E. 2005. Cwrs mynediad: fersiwn y De = South Wales version. CBAC.
[6]
Stonelake, M. and Davies, E. 2005. Cwrs sylfaen : cwrs dechreuol i oedolion sy’n dysgu Cymraeg = a beginners’ course for adults learning Welsh : pecyn ymarfer = practice pack: Fersiwn y De = South Wales version. Uned Iaith Genedlaethol Cymru.
[7]
Stonelake, M. and Davies, E. 2006. Cwrs sylfaen: fersiwn y De = South Wales version. CBAC/WJEC.
[8]
Uned Iaith Genedlaethol Cymru and Welsh Joint Education Committee 1998. Gramadeg Cymraeg cyfoes: Contemporary Welsh grammar. Gwasg Gomer.