@TECHREPORT{langlotztechrep2007,
author = {Langlotz, Tobias and Bimber, Oliver },
title = {Technical Report on Unsynchronized 4D Barcodes},
institution = {Bauhaus University Weimar},
year = {2007},
pdf = {http://e-pub.uni-weimar.de/opus4/files/853/4D-Barcodes.pdf},
}