KOHLER, R. (2014). Jean Piaget. Bloomsbury Academic.
Chicago-čujuhus (17. p.)KOHLER, Richard. Jean Piaget. Bloomsbury Academic, 2014.
MLA-čujuhus (9. p.)KOHLER, Richard. Jean Piaget. Bloomsbury Academic, 2014.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.