2GB Memory RAM Upgrade for the Lenovo Thinkpad R61 Series, T60 Series, T61 Series, X60 Series and X61 Series Laptops (DDR2-667, PC2-5300, SODIMM) at Amazon.com
Lenovo ThinkPad Laptop R61 14.1" Core 2 Duo 2.1GHz 4GB Ram 250GB Windows 10 Home
CMS 8GB (2X4GB) DDR2 5300 667MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with IBM Lenovo® Thinkpad T61, T61P Ddr2 Pc5300 Sodimm - B116
IBM ThinkPad R61 14" Intel T2330 1.6 GHz 4GB RAM 120GB HDD Win XP. Ready to Use | eBay
LENOVO THINKPAD R61 Intel Core 2 Duo 2.00GHz 3GB RAM 80GB HDD Bluetooth 1440x900 | eBay
IBM Thinkpad T61 RAM Replacement - iFixit Repair Guide
Lenovo ThinkPad Laptop R61 14.1" Core 2 Duo 2.1GHz 4GB Ram 250GB Windows 10 Home