@misc{Ryčkov_Pëtr_Ivanovič_(1712-1777)_Опытъ,
 author={Ryčkov, Pëtr Ivanovič (1712-1777)},
 howpublished={online},
 publisher={Rosyjska Akademia Nauk (Sankt Petersburg)},
 language={rus},
 type={starodruk},
 title={Опытъ Казанской Istoriи древнихъ и среднихъ Vreмянъ / сочиненъ Петромъ Pычковымъ [...]},
}