@article{9ad3979dd11444ff87dfc23097390784,
title = "Monitoring of the Einstein cross with the Nordic Optical Telescope",
keywords = "gravitational lensing, quasars: Q2237+0305, techniques: image processing, gravitational lensing, quasars: Q2237+0305, techniques: image processing, gravitational lensing, quasars: Q2237+0305, techniques: image processing",
author = "R. {\"O}stensen and S. Refsdal and R. Stabell and J. Teuber and P. Emanuelsen and L. Festin and R. Florentin-Nielsen and G. Gahm and E. Gullbring and H. Grundahl and J. Hjort and M. Jablonski and A. Jaunsen and A. Kaas and Hannu Karttunen and J. Kotilainen and Eija Laurikainen and H. Lindgren",
year = "1996",
language = "English",
volume = "309",
pages = "59--64",
journal = "Astronomy and Astrophysics",
issn = "1432-0746",
publisher = "EDP Sciences",
}