Roxana Cocan, Joseph O Rourke. Polygonal chains cannot lock in 4D. Comput. Geom., 20(3):105-129, 2001.
@article{CocanO01, title = {Polygonal chains cannot lock in 4D}, author = {Roxana Cocan and Joseph O Rourke}, year = {2001}, researchr = {https://researchr.org/publication/CocanO01}, cites = {0}, citedby = {0}, journal = {Comput. Geom.}, volume = {20}, number = {3}, pages = {105-129}, }