After opening the link and looking at the book I would not consider this a reliable source. There are a lot of dates and places of birth, dates of marriages, colleges/Universities attended, club memberships, etc. but there are no sources listed as to where the information came from, i.e., birth or christening records, marriage records, etc. or the name of an individual who provided the information and their relationship to the person listed. This type of book is best used for obtaining clues for places to look for records on the individuals to document their family history.