Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh loi » thanh hoa, thanh hai, thanh lap
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
xuc ban » duc ban, cuc ban, quoc ban
loi cua » loai cua, hoi cua, doi cua

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 (nang ma)) hoi. ((hieu van) or (hieu va)) cac xuc ban thanh loi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (nang ma)) hoi. ((hieu van) OR (hieu va)) cac xuc ban thanh loi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (nang ma)) hoi. ((hieu van) or (hieu va)) cac xuc ban thanh loi cua viet*.