@TechReport{buelow99citr, author = {T. B{"u}low and R. Klette}, title = {Digital Curves in 3D Space and a Linear-Time Length Estimation Algorithm}, institution = {Computer-Science Department of The University of Auckland, CITR at Tamaki Campus}, type = {Technical Report}, number = {Number 55}, month = {December}, year = 1999, url = {http://www.tcs.auckland.ac.nz/research/techreports/1999/CITR-TR-55.html} }