what is the official language of free republic of wendland , which is the target area of beiträge zur geschichte der deutschen sprache und literatur journal ?
SELECT DISTINCT var_uri where brack_open dbr_Free_Republic_of_Wendland dbo_officialLanguage var_uri sep_dot dbr_Beiträge_zur_Geschichte_der_deutschen_Sprache_und_Literatur dbo_academicDiscipline var_uri brack_close