To search the catalog to find a comprehensive, multi-lingual list of works on Old Church Slavonic, try the following "keyword expert" searches:
"old church" AND (slavic OR slavonic)
kiev* rus AND (language OR linguistic* OR literature).
kiev* rus AND history
[the asterisk * indicates truncation -- it will bring up Kiev or Kievan. You will not need to type in the diacritic after Rus'