All these publications are presented as PDFs. What you will discover, will depend on the publication you search. Some contain parish registers which will include birth, marriage and death records. Other publications recorded the history of specific areas of Wales.
You can search the following publications in this collection:
Episcopal Registers of the Diocese of St David's, Volumes I & II
Highways & Byways in North Wales, published 1898
Notes On the History of the Anglesey Hunt
Parish Registers of Caerwent & Llanfair Discoed, published 1920
Parish Registers of Conwy, published 1900
West Wales Historical Records, various volumes published between 1913 and 1929