All of the files in this subdirectory tree are from Bitsavers:
https://bitsavers.org/pdf/dec/ethernet/decserver_300

Except for DECserver 300 Terminal Server Technical Description from:
http://www.9track.net/decserver/ek-a0367-tm-001.pdf

AND for the 23-52* EPROMs, which are from:
https://9track.net/roms/