The book Elizabeth (Megan Boone) picks up in the Summer Palace is a short novel called "Kashtanka", written by the Russian author Anton Chekhov. It was first published in 1887 and tells the story of the dog Kashtanka who is adopted by a circus clown after being separated from her master. The clown takes good care of the dog and even teaches her some tricks to perform in the circus. During the performance, however, Kashtanka catches sight of her old master and immediately storms out of the ring to go back home with him.
The Gordon Lightfoot song If You Could Read My Mind is featured here. His song Sundown is played in The Cyprus Agency (No. 64) (2014). The lyrics of both have relevance to the particular plot.
The actor playing Red's (James Spader) chief of security Baz, Baz, also happens to be a former CIA officer and veteran US Marine who founded an NGO which rescues kidnapped children in the sex slave trade.