How to convert Unipolar stepper motor into Bipolar stepper motor - YouTube
STEPPERONLINE Nema 17 Stepper Motor Bipolar 2A 59Ncm(84oz.in) 48mm Body 4- Lead W/ 1m Cable and Connector Compatible with 3D Printer/CNC - - Amazon.com
How to connect a stepper motor with exactly 4 wires to Arduino? - Electrical Engineering Stack Exchange