If my math is correct, the number of Bible references add up to something like the following.
100,000: Thompson Chain Reference
100,000: Nave's Topical Bible
200,000: Cruden's Complete Concordance
500,000: Treasury of Scripture Knowledge
But comparing the number of Bible references can lead me down a slippery slope, to be sure. Each of these classic reference books use the concept of references in different ways. I do not want to get all tangled up, so I will avoid the next logical step of defining how each of the four classic reference books use the concept of references. Just let me say, there are differences, at least in my mind.
Better to look at my own personal experience.
For myself, I find that I come away with more useful information when I use Nave's Topical Bible. The other three classic reference books are based upon starting with some existing Bible verse. However, when I do a search with Nave's Topical Bible I find myself starting with a topic, not a Bible verse--seeking an answer to a question. There is a difference, for me at least. Maybe it is the way my mind flows. More often than not, I turn to the Bible to find a Bible reference related to some topic or question in my mind.
But as I refine my search, I find that what I want is to see how similar Bible verses actually differ. As I get the Bible verses down to some small number--like five or ten different verses, it is easier for me to compare what the Bible may be really telling me.
And then the fun begins.