Kempff.

MLA

Kempff, Wilhelm, et al. Kempff. [England] : BBC Legends, [2001]

APA

Kempff, W., Schubert, F., Brahms, J. & Schumann, R. (2001). Kempff. [England] : BBC Legends.

Chicago

Kempff, Wilhelm, Franz Schubert, Johannes Brahms and Robert Schumann. Kempff. [England] : BBC Legends, [2001]