The line "what is this, garbage day?" is a reference to Silent Night, Deadly Night Part 2 (1987) when Ricky (while on a shooting spree) says the infamous line "garbage day!"
The film was partially inspired by the real-life Covina Holiday Massacre which took place on Christmas Eve in 2008.
There's a scene where an elderly man wakes up after not talking for a year to warn his grandson to "watch out". This pays homage to the original 1984 "Silent Night, Deadly Night".
The act of killing someone by pressing them up onto a set of antlers from a stuffed deer head on the wall is a direct homage to the original Silent Night, Deadly Night (1984), when scream queen actress Linnea Quigley was killed in this manner.
Most of the characters are named after members of the famous Leeds United football team from the seventies: Cooper, Giles, Madeley, Revie, Jones, Jordan, McKenzie. In addition, Bremner St and Reaney's Diner are mentioned in the script.