@article{10_5427_jsing_2015_13h,
     author = {Giorgi Khimshiashvili and Dirk Siersma},
     title = {Cross-ratios of quadrilateral linkages},
     journal = {Journal of Singularities},
     pages = {159--168},
     publisher = {mathdoc},
     volume = {13},
     year = {2015},
     doi = {10.5427/jsing.2015.13h},
     url = {http://geodesic.mathdoc.fr/articles/10.5427/jsing.2015.13h/}
}