See:
- Stanislav Iliev, Observations upon the constructional connections of the dolmens in Bulgaria, in: Geoarchaeology and Archaeomineralogy (Eds. R. I. Kostov, B. Gaydarska, M. Gurova). 2008. Proceedings of the International Conference, 29-30 October 2008 Sofia, Publishing House “St. Ivan Rilski”, Sofia, pp. 175-176 - http://mgu.bg/geoarchmin/naterials/34Iliev.pdf
