A-Tech 8GB RAM for Lenovo THINKPAD E540 | DDR3 1600MHz SODIMM PC3-12800 204-Pin Non-ECC Memory Upgrade Module at Amazon.com
SSD Upgrade for Lenovo ThinkPad Edge E540 256GB/512GB/1TB/2TB | eBay
A-Tech 8GB Module for Lenovo ThinkPad T460s Laptop & Notebook Compatible DDR4 2666Mhz Memory Ram (ATMS350781A25978X1) at Amazon.com
CMS 8GB (2X4GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with IBM Lenovo® Thinkpad X130E 23382Bu Notebook Series - C22 at Amazon.com
Lenovo ThinkPad Edge E540 Business Laptop, Intel Core i5-4th Gen. CPU, 4GB RAM, 500GB HDD, 15 inch Display, Windows 10 Pro, Refurbished Laptop
parts-quick 8GB Memory for Lenovo ThinkPad E540 DDR3L 1600MHz PC3L-12800 SODIMM Compatible RAM at Amazon.com