Obviously, the footnotes. With a reference that can then be slotted into the Bibliography.
Or, in the case of two or more slightly different definitions or sets of details, whack them all in the footnotes and slot them into the supposed Reading List as well.
In doing this, one could also acquire a degree of leeway concerning word limits. If you've been set a thousand-worder and delivered fifteen hundred, the length might be questioned. If that happens, one turns and asks What could I have left out?
Of course, that only works if your text is tightly written.
So how does this relate to About The North? I hear The Inquisitive Reader ask.
Simple, but it works on two levels.
How much detail does the individual reader need? That depends on the individual reader.
The Author assumes that anyone who comes to these titles brings with them a certain degree of background knowledge and that this will vary from reader to reader. The Author's job includes explaining the detail to whatever degree is required.