Encouraged by the reasonable success of my first ngram puzzle Assassinate Shakespeare! I've decided to explore the idea further.
Here is a new ngram. Your task is to reproduce it exactly by entering the relevant search terms into Google ngram.
The correct answer will be a link to the Google ngram viewer showing the exact same graph as I have given but with the mystery text filled in.
How to proceed
This puzzle is designed to be difficult but not impossible. I thought my first ngram puzzle was difficult and yet within three hours someone had solved it. This time I decided to pitch the level at those in the community who are super-quick and give them a little more of a challenge.
Finding a solution does not rely on brute-force methods. If you observe all aspects of the diagram carefully and take note of the Knowledge tag, you should be able to arrive at a partial answer and then a very small amount of fine-tuning will complete the solution.