PTŠab 16.b:41[2] :אתייא יחידייא דהכא כסתמא דתמן ויחידייא דתמן כסתמא דהכא‏ : the opinion of the single authority agrees with the anonymous opinion there, and the opinion of the single authority there agrees with the anonymous opinion here
See the entire entry for stām, stāmā n.m. unspecified