Ed Gein & Robert Bloch's novel Psycho
Jack the Ripper, Dr. Crippen, & Christie

Expressionism:
in art
in film:
The Cabinet of Dr. Caligari (1920), directed by Robert Wiene
The Last Laugh (1924), directed by F. W. Murnau
M (1931), directed by Fritz Lang

Soviet montage theory:
Montage theory developed by Eisenstein and Vertov

Influences: films of the 1950s:
Les Diaboliques (1955), directed by Henri-Georges Clouzot
The Night of the Hunter (1955), directed by Charles Laughton
Touch of Evil (1958), directed by Orson Welles
Macabre (1958), and other films directed by William Castle

Psycho sequels:
Psycho II (1983), directed by Richard Franklin
Psycho III (1986) directed by Anthony Perkins
Psycho IV: the Beginning (1990), directed by Mick Garris

Psycho remake:
Psycho (1998), directed by Gus Van Sant

Other films based on or influenced by the Ed Gein story:
Deranged (1974), directed by Jeff Gillen & Alan Ormsby
Ed Gein, aka In the Light of the Moon (2000), directed by Chuck Parello
Silence of the Lambs (1991), directed by Jonathan Demme
The whole sub-genre of slasher movies, including the Nightmare on Elm Street series, the Halloween series, the Friday the 13th series, and the Scream series

Homages to Psycho and Hitchcock (among many):
Dressed to Kill (1980), directed by Brian DePalma
High Anxiety (1977), directed by Mel Brooks
24 Hour Psycho (1993), by Douglas Gordon
The Simpsons, especially the episodes Itchy & Scratchy & Marge in season 2 (parody of the shower scene) and Black Widower in season 3 (parody of the fruit cellar scene)