Między Slavia Latina i Slavia Orthodoxa = Between Slavia Latina and Slavia Orthodoxa. (OCLC #965802272)

Often books whose primary content is in one language (like Polish) will include a table (or even summary!) of contents in another language (like English). This is tremendously helpful to catalogers who cannot read the primary language of the work! It may also be noted as Language of the Content (RDA

546 __ ǂa Text in Polish, with summaries in English.

and encoded with language codes in MARC 043:

041 0_ ǂa pol ǂb eng

041 subfield ǂb is for Language code of summary or abstract, and is repeatable.