course notes (comnet.pdf) ch. 2
kurose & ross, ed. 7, par. 1.2 (maybe)
tanenbaum ed. 5 1.2 network hardware PANs, LANs, etc.
part of cnppts/chapter1.pdf 
Network topologies link - https://www.comparitech.com/net-admin/network-topologies-advantages-disadvantages/