- ShSn:180
- Shelah+Steinhorn, The nonaxiomatizability of $L(Q^ 2_ {\aleph_ 1})$ by finitely many schemata -- Notre Dame J Formal Logic 31 (1990) 1-13
- ShSn:179
- Shelah+Steinhorn, On the nonaxiomatizability of some logics by finitely many schemas -- Notre Dame J Formal Logic 27 (1986) 1-11