5. Onomastique / Étymologie
2004a THE PLACE-NAMES OF CARDIGANSHIRE
2006. Dr. Richard Suggett, enquêteur principal des monuments historiques du Royal Commission on the Ancient and Historical Monuments of Wales (traduit de l’anglais).
“This is the toponymic equivalent of manna from heaven: a rich diet of place-names that will sustain those traversing the sparse historic terrain of medieval and early-modern Ceredigion.” 
“Undoubtedly this book will become the first port of call for those working on farm and parish histories. This is to be expected because of Wmffre’s meticulous recording of sources. For the archaeologist and landscape historian there is much information on antiquities, settlements and boundaries,” 
“interest in place-names has never been greater – as the increasingly dilapidated library copies of Iwan Wmffre’s magnum opus already demonstrate.” 
2006. Dr. Simon Taylor, toponymiste, lecteur (reader) dans la section de celtique et de gaélique de l’université de Glasgow (traduit de l’anglais).
“This is a monumental work, the largest single publication on Welsh place-names to date.” 
“The Introduction includes a detailed exposition on the Welsh spelling system, especially as it relates to place-names, and is a valuable contribution to the on-going debate on the correct representation of place-names of both Welsh and English origin in Welsh orthography. I had not realised just how contentious a hyphen could be!” 
“Iwan Wmffre has carefully collected and systematically presented the raw data for in-depth studies and analyses of manifold aspects of the language, landscape and history of Cardiganshire and beyond, and for this scholars, both amateurs and professional, from many disciplines, and for generations to come, have much reason to be grateful.” 
2005. †Terry James, archéologue du Dyfed Archaeological Trust, puis responsable de l’informatique du Royal Commission on the Ancient and Historical Monuments of Wales et fondateur du Carmarthenshire Place-Name Survey créé sous l'égide du Carmarthenshire Antiquarian Society (traduit de l’anglais).
“This immense three-volume work is the largest corpus of any county to be published in Wales eclipsing B. G. Charles Place-names of Pembrokeshire, which itself runs to 857 pages. Professor (sic) Wmffre’s study of Ceredigion runs to over 1,400 pages. … His emphasis on pronunciation derives from extensive fieldwork over many years where he interviewed some 200 people for oral evidence and pronunciation. These appear in the sources and are listed in the bibliography. His consumption of tea over a decade must have been prodigious!” 
“Having used the work extensively on a parish where I am doing in-depth research (Llanddewibrefi) I can only congratulate the author for the thoroughness of his research which I found exemplary. If all the parishes in the volume are as good, which I do not doubt, then the work will be recognised as a quarry for its vast use of sources. … This tremendous work complements that on Pembrokeshire and will become an essential companion to anyone doing historical or archaeological research in west Wales let alone place-name studies. We can only hope that at some time in the not too distant future a scholar will take on Carmarthenshire, using the society’s computerised place-name database as a starting point, and develop it into a scholarly thorough-going work in the mode of Iwan Wmffre’s Cardiganshire.” 
2005. Richard Morgan, archiviste émérite des Glamorgan Archives, Cardiff (traduit de l’anglais).
“… this is a formidable publication which cannot be ignored. It is a pity, however, that Wmffre wastes so much space in his long-winded descriptive presentation and in unfavourably criticizing the work of others who have contributed so much to place-name study.” [778–79]
“… there is no doubting the meticulous nature of his research reflected in the historical forms which he has placed chronologically under each entry … and in his remarkable use of local oral evidence.” 
2011. Jen Mathias (compte-rendu sur Amazon.co.uk par une historienne amateure du Cardiganshire) (traduit de l’anglais).
“A Cardiganshire Cultural Jewel. / Anyone with an interest in or who is researching house or house names (and the evolution of these names), family history, cultural landscape, local history, or the topographical anatomy of Cardiganshire should look at these volumes which are far more than just a dictionary of place-names. The wealth of information is amazing, and Mr Wmffre's research is clearly meticulous. Apart from being a useful tool when researching a particular local interest/house or place-name, it is also a very enjoyable browsing experience as well. Source texts are cited, together with dates for the properties, and there is an interesting and wide-ranging introduction and explanation, and an extensive bibliography. / Iwan Wmffre's linguistic interests are apparent (see his other book ‘Language and Place-names in Wales’ - also available from Amazon) and as he appears to be an expert in ‘historical dialectology’ I have every confidence that his linguistic interpretations and translations are totally accurate. Part of Mr Wmffre's research methodology was to use the linguistic and historical knowledge or experience of local people and this method accentuates the links between the people, the place-names and the landscape of Cardiganshire culture.”
2009. *Meaty, contributeur pseudonyme d’un forum internet traitant de la généalogie (traduit de l’anglais).
“well just a little update on this and this might help others searching for housenames in ceredigion. a chap called iwan wmffre wrote a series of books not that long ago about all the housenames in ceredigion. its a colossal bit of work that surley deserves an award. anyway i found waun listed as being part of helyg fach, the present day name for a property neighbouring waun. it is listed as being present on an 1811 os map which i have to go to the national library to see.”