Here is an example on ebay of a book that has an index by phone number and even an index by street address. https://www.ebay.com/itm/Vintage-Phonebook-1987-LAS

Here is an example on ebay of a book that has an index by phone number and even an index by street address. https://www.ebay.com/itm/Vintage-Phonebook-1987-LAS-CRUCES-New-Mexico-Phone-Book-POLKS/324436628690 https://www.ebay.com/itm/Vintage-Phonebook-1987-LAS-CRUCES-N...