Double stratification in the MHD flow of a nanofluid due to a rotating disk with variable thickness Tasawar Hayat, Mehwish Javed, Maria Imtiaz and Ahmed Alsaedi Eur. Phys. J. Plus, 132 3 (2017) 146 Published online: 27 March 2017 DOI: 10.1140/epjp/i2017-11408-x