Tied-array holography with LOFAR P. Salas, M. A. Brentjens, D. D. Bordenave, J. B. R. Oonk and H. J. A. Röttgering A&A, 635 (2020) A207 Published online: 03 April 2020 DOI: 10.1051/0004-6361/201935670