The Operators Book

Rowman & Littlefield Publishers

The Operator's Manual for the New Administrator  

Independently published

Operator Handbook: Red Team + OSINT + Blue Team Reference

World Scientific Publishing Company

An Operator Theory Problem Book                  

Independently published

REMINISCENCES OF A STOCK OPERATOR                

Audible

The Operator: The Peri Reed Chronicles, Book 2  

Operator Methods in Quantum Mechanics (Dover Books on Physics) by Martin Schechter (2003-03-28)

Springer Nature

Functional Analysis and Operator Theory          

Forgotten Books

Quartz Operator's Hand-Book (Classic Reprint)    

Working as a CCTV Operator Course Book          

Independently published

Drone Operator's Log Book: A Gorgeous Drone Flight And Maintenance Logbook For Owners Operators And Lovers, A Cool Drone Flight Log Book For Beginner And Professional Drone Operators