This category does not include music for solo cello + accompaniment, nor does it include cello duos.
It is useful to distinguish between “equal” duos (in which the two voices share the protagonism and difficulty) and “solo + accompaniment” duos (in which one voice has all the melodic protagonism while the other voice is simply the harmonic accompaniment). One way to convert any duo into an “equal” duo is to repeat each section or movement with the voices inverted (swapped).
Duos for Cello and Violin   Duos for Cello and Viola    Duos for Cello and Bass