Yegor says in one of the scenes, "A human being should be entirely beautiful: the mind, the body..." This is part of a line said by Michael Astrov in Act II of Anton Chekhov's play "Uncle Vanya" (1896). The entire quotation, very well-known in Russia, goes, "A human being should be entirely beautiful: the face, the clothes, the mind, the thoughts."
This is the second consecutive film by Valeriy Todorovskiy written by Gennadiy Ostrovskiy, after Lyubovnik (2002). As of 2016, Ostrovsky has not written any other films by Todorovskiy. Sergey Garmash plays a supporting role of a military officer in both films. Also, both films touch upon the relationship of a middle-aged father and his teenage son.
The "spooks" that Pavlik sees everywhere aren't only "ghosts". Russian word "dooh" ("spook") has the second meaning that comes from the military argot. It derives from "dushman" - denomination of Afghan soldiers that fought against the Soviets in Afghanistan - and means "enemy". As far as many of Russian veterans of the Afghan war are proceeding their war career in Chechnya, it is now common among Russian troops to designate enemy Chechen soldiers by this word too.