The following publications are possibly variants of this publication:
- Covering with EllipsesAlon Efrat, Frank Hoffmann, Christian Knauer, Klaus Kriegel, Günter Rote, Carola Wenk. algorithmica, 38(1):145-160, 2003. [doi]
- Covering shapes by ellipsesAlon Efrat, Frank Hoffmann, Christian Knauer, Klaus Kriegel, Günter Rote, Carola Wenk. soda 2002: 453-454 [doi]