The standard is – it is copyrighted by ISO. You can purchase the official PDF from:
ISO 11898-3 is a standard for low-speed, fault-tolerant, medium-dependent interface for controller area network (CAN) communication. Here's some proper text about it: iso 11898-3 pdf
Specifies the Medium Dependent Interface (MDI) and Physical Medium Attachment (PMA) . The standard is – it is copyrighted by ISO