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) : Amazon.in: Computers & Accessories
8GB 2X4GB Compatible Memory for Lenovo Thinkpad T61 T61p DDR2 PC2-5300 SODIMM RAM (PARTS-QUICK Brand) at Amazon.com
Amazon.co.jp: 2 GBメモリRam for Lenovo ThinkPad t61 7661シリーズbyアーチメモリ : パソコン・周辺機器
I “think” you enjoy this… T61 (256 Gb SSD Debian 10, RAM 4 Gb) and E14 2021 (upgrade with RAM 16 Gb, 1 Tb M.2 for Windows 11 and 256 Gb SSD for Debian 11, all Crucial) : r/thinkpad
CMS 8GB (2X4GB) DDR2 5300 667MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with IBM Lenovo® Thinkpad T61, T61P Ddr2 Pc5300 Sodimm - B116 at Amazon.com
How to upgrade RAM memory in Lenovo ThinkPad R61 laptop - YouTube
Lenovo Thinkpad T61 Tutorial how to Remove & Hard Drive-Upgrade Memory DDR2 667 MHz - YouTube