Building a Reference Library

Hi, I thought some of you might like to list some of your must-have reference materials for computerized systems.
My focus in the past has been PLC/HMI/SCADA. Now I’m dealing more with ERP, LIMS, and MES.

I currently have these documents:
ISA S-88 Batch Standard
ISA S-95 MES Standard
An assortment of Part-11 documentation from the FDA website.

Any other suggestions? Thanks.

Also from ISPE

ISPE Good Practice Guide: Good Engineering Practice
GAMP® Good Practice Guide: Electronic Data Archiving
GAMP® Good Practice Guide: Testing of GxP Systems
GAMP® Good Practice Guide: Global Information Systems Control and Compliance
GAMP® Good Practice Guide: IT Infrastructure Control and Compliance
GAMP® Good Practice Guide: Validation of Process Controls Systems
Any of the Baseline Guides that cover what you are doing

I also have the ICH Q9 and other Quality references

(IEEE Std 15288-2008) Systems and Software Engineering — System Life Cycle Processes