@article{JGG_2006_10_2_JGG_2006_10_2_a10,
     author = {S. A. Sorby and T. Drummer and R. Molzon },
     title = {Experiences in {Using} {Spatial} {Skills} {Testing} {Instruments} with {Younger} {Audiences}},
     journal = {Journal for geometry and graphics},
     pages = {227--235},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {2006},
     url = {http://geodesic.mathdoc.fr/item/JGG_2006_10_2_JGG_2006_10_2_a10/}
}