I played one time and half the story of New York with Vivian Sinclair.
I encountered a little difficulty that could be easely adressed.
What sources know are linked to scenes.
But the player may not contact their source at the right scene. So the GM has to find the scene about what the player is asking for to its source.
You could just add either an index pages for where the sources intervene (Let say for instance : "Stella Abrams, p.194"). Another way to do that would be to add the source icone on scenes in the scene flow. And while you are there, why not add the scene page number in the corresponding scenes in the scene flow ?