Akopov A. Yu. :
Comparative study of predictive activity in preschool children, adults, and schizophrenic patients
83'3 p.97
Sukhobskaya G. S. :
Psychological aspects of problem learning and development of cognitive activity in adult students
84'5 p.45
Stepanov V. G. :
Symbol's perception by schoolchildren and adults
92'1 p.42