Erik Skydsgaard, J. 1991. Jørgen Bæk Simonsen: Studies in the Genesis and Early Development of the Caliphal Taxation System. Kbh., Akademisk Forlag, 1988, 213 sider. Historisk Tidsskrift. 15, 2 (jan. 1991), 540–542. DOI:https://doi.org/10.7146/ht.v15i2.53308.