1) The tensor product of two spectra, different from the $\wedge$-- product, is introduced in such a way that a K\"unneth theorem holds. 2) Localizations of spectra are treated by using the more algebraic category of chain functors (instead of the category of CW-spectra). 3) The localization of a given chain functor ${\bf K}_*$ can up to chain homotopy be expressed by tensoring ${\bf K}_*$ with the localization of a fixed chain functor $\boldsymbol{\mathbb Z}_*$.
Homology, Homotopy and Applications, Vol. 3, 2001, No. 3, pp. 55-85