Perhaps you should try some spelling variations:
qua phan » cua phan, qua than, quang phan
phan luc » nhan luc, phan duc, phan suc
ban hanh » ban hang
va triet » va thiet, va trien, ve triet
su triet » su viet, su tien, ve triet
thu sac » thu sach, thu san, thu xac
nang xa » lang xa, nang ma, mang xa
luc ban » duc ban, cuc ban, luc bat
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky ((nang xa) or (nang x)) hoi. hieu qua phan luc ban hanh vi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky ((nang xa) OR (nang x)) hoi. hieu qua phan luc ban hanh vi ((va triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: thu sac ky ((nang xa) or (nang x)) hoi. hieu qua phan luc ban hanh vi ((va triet) or (su triet))*.