Richters etudes are all over the place! You can find a good selection on various BBC Legends CD's, for starters try here:

Chopin: Ballade no. 3 in A flat, opus 47;
Scherzo no. 4 in E, opus 54;
Mazurkas nos. 14 - 17, opus 24;
Barcarolle in F-sharp, opus 60;
Debussy: Preludes, Book 1 nos. 1 - 4, 6, 9, 5, 11, 7, 10;
L'Isle joyeuse;
Images, Book II, No. 1 "Cloches à travers les feuilles";
Prokofiev: Dance, opus 32, no. 1;
Chopin: Etude in E, opus 10 no. 3;
Etude in c, opus 10 no. 12
(London, Royal Festival Hall, 10 July 1961)
Chopin: Etude in C, opus 10 no. 1;
Etude in c sharp minor, opus 10 no. 4;
Etude in e flat, opus 10 no. 6;
Etude in A flat, opus 10 no. 10;
Etude in c, opus 10 no. 12
(London, Royal Festival Hall, 27 Jan 1963)
Debussy: Preludes, Book 2 complete;
Preludes, Book 1, no. 9 "La sérénade interrompue"
(the Maltings, Snape, 16 June 1967)
A great 2 CD set
