“…Such materials are usually put into the category of viscoelastic fluids which incorporate fading memory or other classes of complex fluid. However, the field of complex fluids is intensely studied, as is witnessed by the work of Amendola and Fabrizio [1], Amendola et al [2], Anand et al [3], Anand and Christov [4], Christov and Christov [5], Fabrizio et al [6], Franchi et al [7], Franchi et al [8], Franchi et al [9], Gatti et al [10], Jordan et al [11], Jordan and Puri [12], Joseph et al [13], Payne and Straughan [14], Preziosi and Rionero [15], Yang et al [16]. By a complex fluid we include not only those displaying viscoelastic behaviour but also such as nanofluid suspensions, cf.…”