To make the chronology clear:

• The Wikipedia page from before the reference to Chen's article was added: https://en.wikipedia.org/w/index.php?title=Chip%27s_Challeng... — it cites two sources for "coded by Tony Krueger" ("About box from the game") and for "written [by Krueger] in a single summer" (a forum post).

• Chen's article mentions "Tony Krueger is remembered in Wikipedia as the person who ported…", then adds a footnote: “Probably not as widely documented is that he accomplished this without the source code: He reverse-engineered the MS-DOS version and then reimplemented it for Windows.”

• The Wikipedia article then cites Chen's article for this additional information.

It's all fine and proper. I've just edited the citation to make this clear again.