When Howard is talking to his mother about Bernadette while she is in the washroom, the pictures seen on the wall of Howard as a kid are real pictures of Simon Helberg as a child.
This is the first time in the whole series where the viewers can hear Bernadette yell like Howard's mother, although she did an imitation of her in The Boyfriend Complexity (2010).
The word 'putz', as used by Bernadette, is Yiddish slang for 'Dick'.
Penny mentions Howard trying to kiss her and her breaking his nose, which occurred in The Killer Robot Instability (2009).
"The Mystic Warlords of Ka'a" card game was created by the art department and appears in a number of episodes: The Justice League Recombination (2010), The Engagement Reaction (2011), The Flaming Spittoon Acquisition (2011), and The Decoupling Fluctuation (2012)).