One of the greatest guides to the concept of continuity in a specific series is The DisContinuity Guide: The Unofficial Doctor Who Companion by Paul Cornell, Martin Day and Keith Topping, first put out in 1995.
From my point of view the genius of this work is in the way the authors peel back the layers of a complex text like Doctor Who, and start back at the beginning, when we didn't know anything about the series or what it would eventually evolve into.
This allows us to see the ways in which the universe was expanded, sometimes carefully, often times not. We get to see undeveloped themes and the earliest examples of new themes.
Like an evolutionary biologist studying our small, brown furred burrowing human ancestors, we get a look at the way things were without the baggage of the way things are.
Marvel Comics Silver Age DisContinuity 005
Title(s) :
The Coming of the Hulk
The Hulk Strikes!
The Search for the Hulk
Enter... The Gargoyle!
The Hulk Triumphant!
Publication Date/On Sale Date :
May 1962/March 1, 1962
Writer/Artists :
Sources :
Boris Karloff's Frankenstein, Strange Case of Dr. Jekyll and Mr. Hyde, The Golem, The Thing from the Fantastic Four