@ARTICLE{JVLC13,
author = {Giuseppe Della Penna and Daniele Magazzeni and Sergio Orefice},
title = {A general theory of spatial relations to support a graphical tool for visual information extraction},
doi = {10.1016/j.jvlc.2012.11.002},
journal = {Journal of Visual Languages and Computing},
editor = {Elsevier},
pages = {71--87},
year = {2013},
month = {4},
volume = {24},
number = {2}
}