Target Display Mode: Using an iMac as a monitor - YouTube
Amazon.com: HumanCentric VESA Mount Adapter for iMac 24 Inch (Aluminum), iMac 27 Inch (2009, 2010, 2011), LED Cinema Display, Thunderbolt Displays, Replaces Apple iMac VESA Adapter MD179ZM/A, iMac VESA Kit : Electronics
Amazon.com: Willhom LCD Display Port Lvds Cable 593-1028- B 593-1281 Replacement for iMac 27" A1312 Late 2009 Mid 2010 : Electronics
USE MY OLD IMAC AS SECONDARY DISPLAY - Apple Community
2009-2011 27" iMac as an external display | MacRumors Forums
Amazon.com: Odyson - LCD Display Panel Replacement for Apple iMac 27" A1312 (Late 2009) : Electronics
Amazon.com: HumanCentric VESA Mount Adapter for iMac 24 Inch (Aluminum), iMac 27 Inch (2009, 2010, 2011), LED Cinema Display, Thunderbolt Displays, Replaces Apple iMac VESA Adapter MD179ZM/A, iMac VESA Kit : Electronics
Apple iMac (27-inch, unibody, 2009) review: Apple iMac (27-inch, unibody, 2009) - CNET
Apple+iMac+A1225+24%22+Desktop+-+MB418LL%2FA+%28March%2C+2009%29 for sale online | eBay
Review: Apple 27-Inch iMac | WIRED
Use your iMac as a display with target display mode - Apple Support
How to connect your old 2009 imac to new 13" M1 Macbook Pro as an External Monitor. Cheap Hack! Easy - YouTube
Teardown of Apple's Thunderbolt Display finds same LG panel used in 2009 iMac | AppleInsider