Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
nam duc » nam duoc, pham duc, nam thuc
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di 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) or (thuat sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van nam duc va tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van nam duc va tinh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuat sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van nam duc va tinh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van nam duc va tinh vi cua tre*.