@Unpublished{,
author = { Robert Connelly and Erik D. Demaine and Martin L. Demaine and Sandor Fekete and Stefan Langerman and Joseph S. B. Mitchell and Ares Ribo Mor and G{\"u}nter Rote },
title = { Locked and unlocked chains of planar shapes },
year = { 2004 },
month = { August },
}
