2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162521Mahmoodian and Soltankhah $\cite{MMS}$ conjectured that there does not exist any $t$-$(v,k)$ trade of volume $s_{i}< s <s_{i+1}$, where $s_{i}=2^{t+1}-2^{t-i}, i=0,1,..., t-1$. Also they showed that the conjecture is true for $i=0$. In this paper we prove the correctness of this conjecture for Steiner trades.7 pages. to appear in Utilitas MathematicaCombinatorics05B05text