Opto-isolator IC and the right way to test it by Jestine Yong

Testing BJT Transistors with a Multimeter a Video by Anamorphic Square

Testing Transistors with DMM or VOM edited by Sam Goldwasser

How to choose an ESR meter by Condor Audio

ESR Meter Mk.2 Manual by Bob Parker

Blue Ring K7205 Tester Manual by Bob Parker

Bob's ESR Meter Page by Bob Parker

Capacitor, Inductor, Semiconductor Pintrest Pages by Anatek

BadCaps Discussion Forum  by Jelsoft Enterprises Ltd

Kripton Electronics ESR Meters Repository by kripton2035

Kripton Electronics LCR Meters Repository by kripton2035

The "Blue ESR" User Group on Facebook by Electronic Repair - Egypt

How To Make Full Use Of Your ESR Meter by Jestine Yong (Electronic Repair Guide).