Each family entry in the published books may be two or three column inches or more in length, containing pertinent dates and names of children, parents, in-laws and places of birth, residence, occupation, etc. The Bere Peninsula, in southwest County Cork jutting out into the Atlantic Ocean, was a copper mining district in the 19th Century, centered around the Allihies mines. It is not very large in size. Many of the those who emigrated from there pursued the same occupation in the United States. Thus many ended up on the Upper Peninsula of Michigan, Utah, Butte, Montana, and other mining regions.
Some records refer to people in South Africa, Australia and other locations around the world.
The books were not indexed, although they are roughly alphabetized. Mr. O'Dwyer's method was to start at one side of a parish and work his way over to the other. The creation of this computerized index by Mr. O'Dwyer and William Roberts of Oconomowoc, Wisconsin, is a tremendous contribution to the study of Irish family history, over and above his original contributions. Mr. O'Dwyer has the manuscripts for these. As the dates and sources of the information are not normally given in the individual books, this marvelous source cannot be considered to be a good secondary source of information.