  The aim of this article is to study the behaviour of the relative
multifractal spectrum under projections. First of all, we depict a relationship
between the mutual multifractal spectra of a couple of measures $(\mu, \nu)$
and its orthogonal projections in Euclidean space. As an application, we
improve Svetova's result (Tr. Petrozavodsk. Gos. Univ. Ser. Mat., 11 (2004),
41-46) and study the mutual multifractal analysis of the projections of
measures.
