The Stigler spells this the old-fashioned way, like I used to do, with a silent "n" (see previous post).
This spelling has been proven to be and always have been wrong. It's with "mm".
Having ruled out all other explanations, the only possible explanation which that previous link can give for so many people (me included) clearly remembering a time when "mn" was the correct spelling is that we have crossed over from a parallel universe.
Debate Magazine
