May I suggest bookmarking the PHILATELIC SOCIETY OF LANCASTER COUNTY (PSLC) website
https://lcps-stamps.org/library-electronic/ There you will find 200+ FREE philatelic books and publications, from around the world, to download.
The "PHILATELIC LINKS" page
https://lcps-stamps.org/presentatio...telic-links/ provides direct links to 275+ national and international philatelic organizations and exhibits from around the world!
Learn for yourself why the APS recently awarded the PSLC website a GOLD medal for its content.