The 1904 Revival in Wales
This contains two books in one; both written by eyewitnesses to the Welsh Revival of 1904.
The first is: The Awakening In Wales And Some Of The Hidden Springs, by Jessie Penn-Lewis.
Book Two is: The Religious Revival in Wales 1904, by Awstin and other special correspondents of the Western Mail, London.
(As publisher, I should tell you that another book I publish is actually better, which also has two books in one: The Welsh Revival & The Story of The Welsh Revival.)