Board Thread:Editor Board/@comment-3551173-20131004024806/@comment-3551173-20131017012956

Alright the timeline referencing is referencing events, and pick which volumes of light novels you wanna reference events from.

Well if you want a clearer idea:

Volumes 1-2 is Aincrad Arc

3-4 is Alfheim

5-6 is GGO or phantom bullet

7 is Mother's Rosario

8 is Early or Late

9+ is Alicization

Basically pick a volume or part of a volume and reference events from that section.