Characterization of inclusion among Riesz−Medvedev variation spaces

We present a characterization of inclusion among Riesz−Medvedev bounded variation spaces, i.e., we shall present necessary and sufficient conditions for the Young functions ${\phi }_1$ and ${\phi }_2$ so that $R{V}_{{\phi }_1}[a,b]\subset R{V}_{\phi {}_2}[a,b]$ or $R{V}_{{\phi }_1}^{\ast }[a,b]\subset R{V}_{{\phi }_2}^{\ast }[a,b]$.