Some of the soldier's screams you hear after Tidemann calls Captain Holm on his mobile are sound effects from Command & Conquer (1995).
The sound that you hear over Oslo when the troll is near is the sound of flight alert or 'Flyalarmen'. It is mostly used to make people known about an coming threat, like a terror attack, a gas leak or an earthquake. This sound is tested twice a year. The last time it was played for real was in Oslo in 2011. It's actually the exact same as the Swedish VMA. (Important message for the public).
WILHELM SCREAM at 47:13 (After the artillery attack, when the troll kicks the military vehicle into the trees).
The music in the trailer is Edvard Grieg's In the Hall of the Mountain King.
The character Dr. David Secord played by Billy Campbell (as Ollie Campbell) is named after Campbell's role Cliff Secord in the movie "The Rocketeer" (1991) and Dave Stevens the creator of the Rocketeer comic books. Screenwriter Espen Aukan is a huge fan of the 1991 movie, and adjusted the character in the screenplay when he knew Campbell was cast. When first given the screenplay, Campbell received a copy with the fake title "The Rocketeer II: The Last Flight" on the cover.