de Vries, A.A.F.; Horzinek, M.C.; Rottier, P.J.M.; de Groot., R.J. 1997. The genome organisation of the Nidovirales: similarities and differences between arteri-, toro-, and coronaviruses. Seminars in Virology. 8: 33–547. CiteSeerX10.1.1.462.1825. doi:10.1006/smvy.1997.0104
de Vries, A.A.F.; Horzinek, M.C.; Rottier, P.J.M.; de Groot., R.J. 1997. The genome organisation of the Nidovirales: similarities and differences between arteri-, toro-, and coronaviruses. Seminars in Virology. 8: 33–547. CiteSeerX10.1.1.462.1825. doi:10.1006/smvy.1997.0104