Tutorial: How to upgrade ram in a T61 Thinkpad - YouTube
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) - Walmart.com
IBM Thinkpad T61 RAM Replacement - iFixit Repair Guide
My Decade Driver: a 2008 vintage Lenovo Thinkpad T61! New battery, SATA SSD, and RAM upgrade. A bit sluggish but it works! : r/retrobattlestations
8GB 2X4GB Compatible Memory for Lenovo Thinkpad T61 T61p DDR2 PC2-5300 SODIMM RAM (PARTS-QUICK Brand) at Amazon.com
IBM Thinkpad T61 RAM Replacement - iFixit Repair Guide
4GB kit (2GBx2) Upgrade for a Lenovo ThinkPad T61 Series System (DDR2 PC2-5300, Non-ECC, ) at Amazon.com
I found her back my beloved Thinkpad T61 : r/thinkpad
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
How to replace fan in Lenovo ThinkPad T61 – Inside my laptop