Joel (Timothy Olyphant) asks if anything good besides tennis players ever came out of Serbia. Olyphant is a huge tennis fan and frequently plays in celebrity matches for charity.
The title and Gary's analogy about being married to the Queen of England is based on the marital strife depicted in The Crown (2016). Show creator and writer Victor Fresco is a devoted fan of the series.
Ramona mentions moving to Seattle. In the show iZombie (2015), there is a zombie outbreak in Seattle.