ST4118L1804-A - Nanotec - Stepper Motor, High Torque, DC
Amazon.com: Twotrees Stepper Motor Nema 17 Motor High Torque 1.5A (17HS4401) 42N.cm (60oz.in) 1.8 Degree 38MM 4-Lead with 1m Cable and Connector for 3D Printer : Industrial & Scientific
How Stepper Motors Work
Nema-17 Stepper Motor
Why microstepping in stepper motors isn't as good as you think - EDN