IBM - ThinkPad R40 Battery | Complete Battery Source
IBM ThinkPad R32 ThinkPad R40 Replacement Battery: BatteryClerk.com
ThinkPad R review: ThinkPad R - CNET
A bit of browsing with the R40 running XP : r/thinkpad
IBM R40 Thinkpad laptop - Vintage computer - Catawiki
IBM Thinkpad R40 2682 Laptop Battery by Powerwarehouse - Premium Powerwarehouse Battery 8 Cell - Newegg.com
IBM ThinkPad R40 Laptop Computer 2.2GHz DVD Pentium 4 M(id:2580539) Product details - View IBM ThinkPad R40 Laptop Computer 2.2GHz DVD Pentium 4 M from Asfdffds - EC21