![134698](https://sdvigpress.org/images/creator/_default.jpg)
References
Jan Boom
Cognitive development![Open Access Link](images/OAlink.png)
1997
in: Philosophy of development, Dordrecht : Springer
![Open Access Link](images/OAlink.png)
Two conceptions of stage structure and the problem of novelty in development![Open Access Link](images/OAlink.png)
1990
in: Recent trends in theoretical psychology, Dordrecht : Springer
![Open Access Link](images/OAlink.png)