Closure to the discussion on "The effect of double stratification on boundary-layer flow and heat transfer of nanofluid over a vertical plate" [Comput. Fluids 86 (2013) 433–441] and on "Hydromagnetic bioconvection of nanofluid over a permeable vertical plate due to gyrostatic microorganisms" [Comput. Fluids 95 (2014) 88–97]. (21st December 2015)