Ok, trying to clarify/narrow down what the usual undergrad/grad level of depth is with what's provided, so reply doesn't seem a bit crude/off-topic.
It's hard to do recommendations without defining/clarifying what the usual undergrad/grad level of depth is.
aka expected backround / prior knowledge / certifications to have to understand the next step beyond the usual / area of knowledge
aka telecommunications, engineering, science, information systems, technical certification such as cisco CCNA.
As presented, looking for non-survey/non-introductory books.
As presented, this spans the full range of technology degrees/technology applications.
Just staying within one of the disciplines below would
a bit broad aka multi course catelog for just a specific area of study.
some areas the above fall under: electrical enginering, computer engineering, systems engeineering, computer scientist, data scientist, information systems, data science, technical certifications for things such as Cisco and/or telecommunications)
Suggestions per information/scope defined:
1) Take a look at what some of the freely available online classes use for resources.
https://www.edx.org/
https://www.openculture.com/freeonlinecourses
https://oedb.org/open/
2) suggested information available for learning/earning a certification
3) university pages containing course outlines/sylabus pages would help.
Ultimate bent would be to feed what's found into a websearch to find related things.