You will have to write to Barbara Kaye for her "other sources":
BarbaraK1775@aol.comBarbara writes, "Descendants of John Waterbury--This is a text file I transcribed from the "Jonathan Waterbury Genealogy" by Grace A. Waterbury and Edwin M. Waterbury and other sources."
The following is the book she refers to, it is available for viewing on Heritage Quest and probably other sites:
Jonathan Waterbury genealogy : ancestry and some of the descendants of Jonathan Waterbury of Nassau, New York (1766-1825) with incidental matter concerning the origin of the Waterbury family and its early history in Europe and America and notes of the descendants of Joseph Waterbury (1778-1829) of Nassau, N.Y. and Roger Morey (1610-1669) of Providence, R.I.
Compiled by Grace Adelle Waterbury and Edwin M. Waterbury; Oswego, N.Y.: Published for the family for private distribution by Palladium-Times, 1930, 364 pgs.