Panin referred to the people of this kingdom as great warriors and fighters.
Audley's Russian opponent, Professor Panin, also makes repeated appearances, and a recurring plot in the later novels concerns the "Debrecen List" of people who may, or may not, have attended a spy school in Debrecen, a city in eastern Hungary.
In 1890, Panin claimed to have discovered numerical patterns in the Hebrew text of the Psalms, and soon afterwards in the Greek text of the New Testament.
He receives a letter from Vladimir Lenin, in which the latter expresses his regret regarding Panin's being away from the Navy.
Where The Atrocity Archives was written in the idiom of Len Deighton and The Jennifer Morgue was a pastiche of Ian Fleming's James Bond novels, The Fuller Memorandum is a homage of sorts to Anthony Price's Dr David Audley/Colonel Jack Butler series of spy thrillers, and features two minor characters named Roskill and Panin, names which appeared as recurring characters in Price's series.