the tomb of a medieval Polish king
... that of 12 experts who opened the tomb of a medieval Polish king in 1973, 10 died prematurely?
... that of 12 experts who opened <b id="mwAc4"><a href="./Tomb_of_Casimir_IV_Jagiellon" id="mwAc8" rel="mw:WikiLink" title="Tomb of Casimir IV Jagiellon">the tomb of a medieval Polish king</a></b> in 1973, 10 died prematurely?