Buchheim, Robert K.; Gartrelle, Gordon M. (July 2011). "846 Lipperta: A Very Slow Rotator". The Minor Planet Bulletin38 (3): 151–153. Bibcode2011MPBu...38..151B. ISSN1052-8091.
Buchheim, Robert K.; Gartrelle, Gordon M. (July 2011). "846 Lipperta: A Very Slow Rotator". The Minor Planet Bulletin38 (3): 151–153. Bibcode2011MPBu...38..151B. ISSN1052-8091.