The Araucaria Project. Binary Classical Cepheids in the LMC
  The status of our work on binary classical cepheid systems in the Large Magellanic Cloud is presented. We report on results from our follow up of two eclipsing binary cepheids OGLE-LMC-CEP-0227 and OGLE-LMC-CEP-1812. Here we presented for the first time confirmation that a third cepheid OGLE-LMC-CEP-2532 is a true eclipsing binary cepheid with a period of 800 days. Two other very good candidates for eclipsing binaries detected during OGLE-IV survey are also discussed. 
D. Graczyk, B. Pilecki, G. Pietrzy\'nski, W. Gieren, P. Konorski, I.   Soszy\'nski, A. Udalski and A. Gallenne
astro-ph.SR