Satoru Kuroda An Independence Result on Weak Second Order Bounded Arithmetic. 183-186 2001 47 Math. Log. Q. 2 http://dx.doi.org/10.1002/1521-3870(200105)47:2<183::AID-MALQ183>3.0.CO;2-Z db/journals/mlq/mlq47.html#Kuroda01