The repeated phrase "Agents of Nothing" in dialogue is a reference to the "Secret Warriors Vol. 1: Nick Fury, Agent of Nothing" collected edition that contains the story arc written by Jonathan Hickman, originally published in six parts in 2009. In the story arc, HYDRA is revealed to have infiltrated S.H.I.E.L.D. after World War II.
The coordinates sent to Agent Coulson's badge point to a nameless road in eastern Ontario, Canada less than 20 miles from the border of Quebec.
John Garrett mentions Johnny Horton, a criminal who gave himself lion paws for hands. In the comics, Johnny Horton is the supervillain Griffin.
This is the first appearance of Eric Koenig outside of the comic books. In the comics he had been part of the Howling Commandos and joined S.H.I.E.L.D. with Nick Fury.
Adrian Pasdar, who plays Glenn Talbot, is no stranger to working on superhero-based projects. He is also known for playing Nathan Petrelli in Heroes (2006) and has been the voice of Tony Stark/Ironman on many projects such as Avengers Assemble (2012), Ultimate Spider-Man (2012), Lego Marvel Super Heroes (2013), and Phineas and Ferb (2007)'s Marvel special.