Four quadrant phase mask K-band coronagraphy of NGC 1068 with NAOS-CONICA at VLT D. Gratadour, D. Rouan, A. Boccaletti, P. Riaud and Y. Clénet A&A, 429 2 (2005) 433-437 Published online: 17 December 2004 DOI: 10.1051/0004-6361:20041820