Time has moved on from reading standard route documents. Get Flight Plan Pro. That is what all modern IFR pilots use.
ATC tend to ignore the published airway routes on the day anyway - traffic in CAS is managed tactically using radar.
If you are a keen reader of the route docs, you may be able to develop a Eurocontrol-acceptable route that way but this is hard work and there is no guarantee it will be accepted because of short-notice airway blockages etc.
It was realised a few years ago that there is only one practical way to develop valid IFR routes, and that is starting with an airway database, running a maze algorithm on that, applying published restrictions, submitting that to Eurocontrol for validation, and parsing the inevitable error messages and amending the route iteratively, with level changes if that helps.
What Eurocontrol have done is in effect set up a city with a load of one-way and timed- access streets, but there are no roadsigns, and no maps published
The only way to find out valid routes is to drive around and then wait for the county counrt summonses to arrive for driving the wrong way down a one-way street, etc. and then iteratively amend one's routing. No kidding.