RAM Upgrades For Apple MacBook (2009 - 2010) from OWC
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com
Timetec 8GB KIT(2x4GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC3-8500 CL7 for Mac Book,
MacBook Pro : retirer ou installer de la mémoire - Assistance Apple (FR)
A-Tech for Apple 2GB DDR3 1067MHz / 1066MHz PC3-8500 SODIMM Memory RAM Module for MacBook, MacBook Pro, iMac, Mac Mini - (Late 2008, Early 2009, Mid 2009, Late 2009, Mid 2010) Models at Amazon.com
How to Upgrade Mac Pro Memory (Early 2009/MacPro4,1): EveryMac.com
macOS Big Sur 11.2.3 on a late 2009 MacBook : r/mac
A-Tech for Apple 4GB Kit (2X 2GB) DDR3 1067MHz / 1066MHz PC3-8500 SODIMM Memory RAM