What has the author Frederik Gotschalk Knudtzon written?

It appears you're asking about a fictional author. There is no record of an author named "Frederik Gotschalk Knudtzon".

It's possible you've misremembered the name or there's a typo. Could you please double-check the name or provide any additional information? For example, do you remember any of the author's books or the genre they wrote in?