Recently Das gives sufficient
conditions for (N,rn) ⊆ (N,pn)(N,qn) or (N,pn)(N,qn) ⊆ (N,rn), and for
|(N,Pn)|∼|(N,pn)(C,1)|. The purpose of this paper is to give sufficient
conditions for |(N,rn)|⊆|(N,pn)(N,qn)| or |(N,pn)(N,qn)|⊆|(N,rn)|.
The results obtained here are also absolute summability analogues of Das’
theorems.