I am writing a scientific paper and must refer to a page of Wikipedia (WP for short). Should I write "WP page" or "WP's page"? "WP's page" seems to me to be correct, but somehow it sounds strange...
I'm not so sure about the abbreviation WP, but this is a question about a common process in the development of the English language where a noun, especially a genitive becomes functionally an adjective.
For example, I am typing on a computer keyboard. The intent here is "computer's keyboard" or "keyboard of the computer" -- both being the two forms of genitive in English. But over time the genitive noun "computer's" have become shortened to simply an adjectival form of the noun, "computer keyboard."
This morning I drove to work in a car, powered by an engine. The engine was the "car's engine" but we usually just call it in the shortened form "car engine". In Washington DC is a monument to our 16th President, but today it is not called Lincoln's Memorial, it is called the Lincoln Memorial. It was paid for by the United States' government (genitive), but is now managed by the United States government.
If you had a web site Fernando, a page on it would be Fernando's page, because you are not as well known as Wikipedia. However, Wikipedia is well known and ubiquitous enough that I think Wikipedia page would be considered the normal usage.
With your abbreviation though, it might not work as well.