| Title | Journal | Journal Categories | Citations | Publication Date |
|---|---|---|---|---|
| 10.1007/BF00460707 | 1982 | |||
| A Test with Selected Topological Properties of Piaget's Hypothesis concerning the Spatial Representation of the Young Child | Journal for Research in Mathematics Education |
| 9 | 1976 |
| Untersuchungen zur Stellung der Topologie im geometrischen Anfangsunterricht | 1981 | |||
| The Development of the Concept of Space in the Child | 1970 | |||
| The Child's Conception of Space | 1956 |