Any researcher doing Connecticut genealogy research, especially prior to around 1850 has probably heard of the Barbour Collection. They are the Vital Records for Connecticut. Over the years, I have found my ancestor, JOANNAH RUTTY, wife of HENRY FARNHAM listed in two different sources, and both correctly named the Barbour Collection.
In an attempt to explain, I will show copies of the two sources for the above individual. When I first began researching this line, I used the Barbour Collection at the New England Historic Genealogical Society's Library (NEHGS). This collection consists of about 110 maroon bound books, one for a town or city in Connecticut, but not all towns are in this series (photos taken at NEHGS).
Within these books, the surnames are in alphabetical order, then the names, indicating whether it is a birth, marriage or death, and followed by the volume and page number. Unfortunately, when I first began sourcing this name and using the book for Killingworth, Connecticut, I just used the page number (Pg. 31) from the book as the source. The page I used is shown below, and Joannah's name has an arrow by it.