▁World ▁War ▁II , ▁as ▁well ▁as , ▁all ▁matters ▁of ▁the ▁Polish - J ew ish ▁relations ▁and ▁J uda ism ▁in ▁Poland . ▁ ▁From ▁ 1 9 9 4 , ▁Lib ion ka ▁worked ▁in ▁the ▁Polish ▁Contempor ary ▁History ▁section ▁of ▁the ▁Institute ▁of ▁History ▁of ▁the ▁Academy ▁of ▁Sciences ▁and , ▁since ▁ 2 0 0 0 , ▁in ▁the ▁Bureau ▁of ▁Public ▁Education ▁of ▁the ▁Institute ▁of ▁National ▁Rem emb rance ▁( Inst yt ut ▁Pam ie ci ▁Narod owej ) ▁in ▁Lub lin . ▁ ▁His ▁articles ▁appeared ▁in ▁„ D zie je ▁Naj n ows ze ”, ▁„ B iu let yn ▁Ż I H ”, ▁„ Pol ska ▁ 1 9 4 4 / 1 9 4 5 - 1 9 9 9 ”, ▁„ T yg od nik ▁P ows zech ny " ▁and ▁in ▁„ Y ad ▁V ash em ▁Studies ”. ▁In ▁ 1 9 9 8 ▁he ▁wrote ▁his ▁Ph . D ▁dis sert ation ▁entitled ▁" The ▁' J ew ish ▁Question ' ▁in ▁Polish ▁c atholic ▁Press ▁in ▁the ▁ 1 9 3 0 s ." ▁ ▁Publications ▁" Pol ska ▁lud ność ▁chr ze ści ja ńska ▁wob ec ▁ek st erm in acji ▁Ż yd ów ▁– ▁dy str y kt ▁lub el ski " ▁( Pol ish - Christ ian ▁Population ▁and ▁the ▁Naz i ▁Ex termin ation ▁of ▁Jews ▁in ▁Lub lin ▁District ) ▁Arm ia ▁K raj owa ▁i ▁De leg atura ▁R