Two kinds of piano parts are available, one for double bass in solo tuning (F#, B, E, A), [Full Score]
and the other for double bass in orchestral tuning (E, A, D, G). [Piano reduction]
The separate part for piano is for double bass in solo tuning.
https://www.universaledition.com/Werke/Oberek/P0268195
Recording Notes
live at Composition Concert, recorded with Double Bass in solo tuning