Saul jokes to his new criminal partners about being buried in a sandstorm for a thousand years, alluding to the poem "Ozymandias" which gave the most famous episode of Breaking Bad (2008) its title, Ozymandias (2013).
Saul's (Jimmy McGill) former secretary Francesca refers to an offshore shell company that Saul had hidden money, "Tigerfish Corporation." Tigerfish was the name of the submarine in the 1968 film Ice Station Zebra (1968) that Jimmy McGill and Kim Wexler were always watching.
One of Alfred's documents shows he has money invested with Cherkis Investments, a company named after "Better Call Saul" writer Ann Cherkis.
Parts of the episode seem to have been adopted from the "Better Call Saul: Client Development" Graphic Novel which was released during Season 1, especially Mike's background check of Walter and Jesse.
Jimmy/Gene uses his old alias, Viktor (with a "k") during his cons. This is a callback to Season 2, Ep 1 (Switch) when he & Kim posed as brother & sister, Viktor & Giselle St. Clair & con an obnoxious stock agent into paying for an expensive meal & drinks.
Thomas Schnauz: Writer/director, in the montage showing various credit cards and driver licenses laid out, his face can be seen on a license belonging to "Carl Haven."