@article{Guttesen_1987, title={Information Bulgaria: a short encyclopaedia of the People’s Republic of Bulgaria. Ed. by the Bulgarian Academy of Science.}, volume={87}, url={https://tidsskrift.dk/geografisktidsskrift/article/view/44483}, journal={Geografisk Tidsskrift}, author={Guttesen, Rolf}, year={1987}, month={jan.} }