Resources for Literature Review - Studying BSc. in Process Instrumentation & Automation

Hi All,

Currently studying final year BSc. Process Instrumentation & Automation. Doing a Literature Review at the moment and I am looking for some Online resources/Websites for the following topics:

  1. Flow Measurement - Flow Switches/Electromagnetic Flowmeters/Coriolis Flowmeters
  2. Level Measurement - Level Switches/Ultrasonic Level/Guided Radar Level/Capacitance Level
  3. Industrial Networks - OSI Model/Protocols/Profibus/Profinet/AS-i/IO-Link

I have some great resources from Siemens, Endress+Hauser, YouTube etc...

Any more access to information on the above topics would be greatly appreciated.