What is the abbreviation for Proceedings the institution electrical engineers?

Looking for the shorthand of Proceedings the institution electrical engineers or how to abbreviate it? We have 3 shorthands for Proceedings the institution electrical engineers.

PROC INST ELECTR ENG — Proceedings of the Institution of Electrical Engineers
PROC IEE — Proceedings of the Institution of Electrical Engineers
PROC ISS — Proceedings of the Institution of Electrical Engineers