found: Work cat.: Heim, N.M. Invocation, c1993:t.p. (for contra-bass clarinet)
found: New Grove dict. mus. inst.(contrabass clarinet, sometimes called pedal clarinet)
found: Marcuse. Musical instruments, 1975(Contrabass clarinet)
found: 2001545331: Ritter, R. Long, long ago, c1999(B-flat contra-bass clarinet)
found: 2001545332: Ritter, R. Long, long ago, c1999(E-flat contra-alto clarinet)
found: Grovemusic.com WWW site, Apr. 15, 2003(Contrabass clarinet: A member of the clarinet family pitched two octaves below the soprano clarinet in B♭ (or one below the B♭ bass clarinet) or an octave below the alto clarinet (in E♭). The B♭ variety is sometimes called "pedal clarinet")