Marvel Knights (vol. 1) #2 (Aug. 2000):
“Thunder Below”
by Chuck Dixon, Eduardo Barreto, Klaus Janson

(pg. 11) Van Kline employee: "Uh... He wants to talk to you."
Mr. Van Kline (on phone): "Is this Mr. Ulik I'm speaking to? Mr. Dryden seems to think I have something of value that belongs to you. He also tells me you have placed him under considerable duress to retrieve it. If I had this Horn of Auohumla that you claim is yours..."

Black Widow: "These monsters are working with a purpose. And I don't think it's anything Giuliani has in mind. I saw we call in SHIELD and let them figure out what these tunnels are about."

Shang-Chi: "My father often used burrows such as these to dark purpose."
Dagger: "Your father?"
Shang-Chi: "A long story for another time."

Mr. Van Kline (on phone): "Is this Mr. Ulik I'm speaking to? Mr. Dryden seems to think I have something of value that belongs to you. He also tells me you have placed him under considerable duress to retrieve it. If I had this Horn of Auohumla that you claim is yours I would need proof of ownership. Otherwise I would be forced to ask..." [more]
Horn is shown in Van Kline's possession. Multiple references to Horn of Auohumla, although not always by its full name. Ulik's efforts to get the Horn are story's central plot point.

Black Widow: "These monsters are working with a purpose. And I don't think it's anything Giuliani has in mind."

(pg. 17) Punisher: "I thought you were going to call in the Avengers."
Daredevil: "They're busy this week."
Punisher: "Too busy to save the city from monsters?"
Daredevil: "Maybe they just wouldn't come running on the word of a murdering psycho."
(pg. 22) Daredevil: "Maybe I should have called the Avengers."