Please read Alexey Sklyarenko's annotations on Pale Fire, Ada and other Nabokov works here.
Describing King Victor’s last visit to Villa Venus (Eric Veen’s floramors), Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions a line composed by Seneca that King Victor (the Antiterran ruler of the British Commonwealth) wrote in the Shell Pink Book:
According to Van Veen (the narrator and main character in VN’s novel Ada, 1969), all the hundred floramors (palatial brothels built by David van Veen, a wealthy architect of Flemish extraction, all over the world in memory of his grandson Eric) opened simultaneously on September 20, 1875:
Describing his bicycle ride with Ada and visit to a Russian traktir in Gamlet (a half-Russian village near Ardis Hall), Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions a coachman who came straight from a pretzel-string of old novels:
‘We must now find our bicycles,’ said Van, ‘we are lost "in another part of the forest."’
‘Oh, let’s not return yet,’ she cried, ‘oh, wait.’
‘But I want to make sure of our whereabouts and whenabouts,’ said Van. ‘It is a philosophical need.’
Describing the Night of the Burning Barn (when he and Ada make love for the first time), Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions telegas (pl. of telega, a cart) among the vehicles used by the inhabitants of Ardis Hall to reach the site of the fire:
With the tartan toga around him, he accompanied his black double down the accessory spiral stairs leading to the library. Placing a bare knee on the shaggy divan under the window, Van drew back the heavy red curtains.
Like her grandmother, Marina (in VN's novel Ada, 1969, Van's, Ada's and Lucette's mother) likes to have her hair done in the open:
Describing his last night at Ardis, Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions his dream in which he saw himself on a mountain smothered in snow, with people, trees, and a cow carried down by an avalanche:
Before the family dinner in "Ardis the Second" Demon Veen (in VN’s novel Ada, 1969, Van's and Ada's father) calls Blanche (a French handmaid at Ardis) "a passing angel:"
Demon shed his monocle and wiped his eyes with the modish lace-frilled handkerchief that lodged in the heart pocket of his dinner jacket. His tear glands were facile in action when no real sorrow made him control himself.
In VN's novel Pnin (1957) Laurence Clements (Pnin's landlord) compares the night sky to a fluorescent corpse:
It was a fair fall night, velvet below, steel above.
Joan asked: 'You're sure you don't want us to give you a lift?'
'It's a ten-minute walk. And a walk is a must on such a wonderful night.'
The three of them stood for a moment gazing at the stars.
'And all these are worlds,' said Hagen.
When Van Veen (the narrator and main character in VN’s novel Ada, 1969) visits Philip Rack (Lucette's music teacher who was poisoned by his jealous wife Elsie) in Ward Five of the Kalugano hospital (where Van recovers from a wound received in a pistol duel with Captain Tapper), the male nurse Dorofey reads an article in the Russian-language newspaper Golos (Logos):
Before the family dinner in "Ardis the Second" Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions a fresh oeillet in his father's lapel eye:
Demon shed his monocle and wiped his eyes with the modish lace-frilled handkerchief that lodged in the heart pocket of his dinner jacket. His tear glands were facile in action when no real sorrow made him control himself.