When you add a story idea you'll need to say where it goes. To identify an existing page, just use the URL. For example, "journey-to-center/200.html"
Stories that link other stories together
Linking stories is my absolute favourite thing. Because it makes the game world feel rich: you are not stuck on rails, forced to read in straight line. For example, "Journey to the Center of the Earth" connects to "Goddess of Atvatabar" as they both feature underground worlds.
You can branch off at any time. For example, at the start of the book, instead of looking at the piece of paper that falls out of the book (the paper with she secret code), you could maybe jump right into the book he is reading, "The Chronicle of The Kings of Norway" and join the saga of gods and monsters. And later when the professor reads books about code breaking, maybe one of them is a famous book about real code breaking and spies?
Can you think of ways to link existing stories? Create your own mini-story and I'll add it!