Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
hanh hai » nhanh hai, hang hai, hanh tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((nang x) or (lang xa)) hoi. hieu van cau duc va ((hanh hai) OR (thanh hai)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (lang xa)) hoi. hieu van cau duc va ((hanh hai) OR (thanh hai)) cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang x) or (lang xa)) hoi. hieu van cau duc va ((hanh hai) OR (thanh hai)) cua triet*".