OWC 6GB (2GB + 4GB) PC8500 DDR3 1066MHz SO-DIMMs Memory Compatible with Late 2008, Early 2009, Early 2010 MacBook, MacBook Pro Unibody Models, 2009/2010 Mac Mini, 2009 iMac Models
MacBook Pro: How to remove or install memory - Apple Support
MacBook Pro Mid 2009 15 inch 8GB RAM - 500GB NanoDrive - 2.66 Core 2 Duo | eBay
Apple MacBook Pro 15" Mid 2009 Laptop Intel Core 2 Duo 2.53GHz 4GB RAM 500GB-HDD | eBay
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com