Investigating the surface inhomogeneities of the contact binary SW Lacertae - I. Doppler imaging H. V. Şenavcı, G. A. J. Hussain, D. O’Neal and J. R. Barnes A&A, 529 (2011) A11 Published online: 21 March 2011 DOI: 10.1051/0004-6361/201015753