@article{ELMA_1971__26_141017,
     author = {W. Wunderlich},
     title = {Starre, kippende, wackelige und bewegliche {Gelenkvierecke} im {Raum.}},
     journal = {Elemente der Mathematik},
     pages = {73--83},
     publisher = {mathdoc},
     volume = {26},
     year = {1971},
     zbl = {0213.51203},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1971__26_141017/}
}