what is the main common interests of the moḥammad ḥosayn kāšef-al-ḡeṭāʾ and al-biruni ?
SELECT DISTINCT var_uri where brack_open dbr_Moḥammad_Ḥosayn_Kāšef-al-Ḡeṭāʾ dbp_mainInterests var_uri sep_dot dbr_Al-Biruni dbp_mainInterests var_uri brack_close