There is a lot of space between no acknowledgment at all like this article and tracing down the exact origin of who and when invented to null bit map in what system.
Your version comes off as self promotion, going into detail how to implement a the technique with out once calling it a common technique or even mentioning its widely used in the industry to solve the problem you are solving.
It would be like saying finding rows in storage is slow so we implemented a b-tree in a separate structure for certain columns and go into detail how to create a b-tree, calling it a "trick" while never once acknowledging the is the most common form of indexing in RDBMS's, would you understand how this would seem strange?
