Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh hai » thanh phan, thanh hoa, thanh san
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, dua tren
cam duc » cam xuc, cao duc, pham duc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam

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 xa) or (nang ma)) hoi. hieu ve cam duc va thanh hai ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cam duc va thanh hai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang ma)) hoi. hieu ve cam duc va thanh hai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang ma)) hoi. hieu ve cam duc va thanh hai ((cua tre) OR (cua triet))*.