The best book I've yet found in English concerning the Oriental Orthodox approach to Chalcedon and Christology more generally is Christology and the Council of Chalcedon by Fr. Shenouda Maher Ishak. It's about $50 via Amazon right now, but at over 700 pages is well worth the price. Fr. Shenouda is a serious academic scholar with a Ph.D. from Oxford who has published on church topics for over 40 years and represented us in an official capacity in ecumenical talks with the Chalcedonians in the more recent past. I would start there, together with a reputable academic translation of the acts of Chalcedon itself (I have the Gaddis and Price translation in two volumes that was published as part of Liverpool University's 'Translated Texts For Historians' series and would recommend that, though I'm sure it's not the only one that's available).
There are other works that would be good to know if you've already got a bit of background in the events surrounding Chalcedon, like Karekin Sarkissian's The Armenian Church and the Council of Chalcedon (published in the 1960s; can't remember the exact year at the moment), which is useful precisely because the Armenians are Oriental Orthodox despite not having been present at Chalcedon in the first place (due to the political problems of being ruled by the Persians at the time, who prevented fraternizing between their subjects and the enemy Byzantines insofar as was possible by arresting and imprisoning bishops and priests). So it can give you a different and perhaps more complete picture of Chalcedon from what would come to be known as the 'OO side', as they weren't involved in initial rupture (they wouldn't formally reject Chalcedon until 506, since they didn't know the details of what it had decided until their own Council of Dvin in that year), have never considered St. Dioscorus to be a saint, etc.
