[Raymond]

Originally Posted by mbyron

I'm glad you didn't point out the difference. "Whoever" was the subject of its clause, and thus correctly in the nominative case. "Whomever" would have been wrong.

Originally Posted by M&M Guy

Hmm, that's not the way I learned it. "Whomever" should be the subject of a clause, while "whoever" is the subject of the verb.

Whoever and Whomever | Grammar Rules

I'm with byron on this one. "Whoever" is the subject of the verb "authored". In fact, "Whoever" is also the subject of the verb "failed".