  We extend classical results by Lavrent'ev and Kufarev concerning the product
of the conformal radii of planar non-overlapping domains. We also extend
relatively recent results for the case of domains in the $n$-dimensional
Euclidean space, $n \geq 3$, with conformal radii replaced by harmonic ones.
Namely, we get analogues of these results in $n$-dimensional Euclidean space in
terms of $p$-harmonic radius. The proofs are based on technique of modulii of
curve families and dissymmetrization of such families.
