Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, le thanh
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
va tinh » may tinh
ve cac » va cac, vien cac
va cam » va cham, va cac, va cao
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: te sach ky nang ma hoa. hieu ((ve cac) or (va cam)) luc ((va thanh) OR (va tinh)) vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ma hoa. hieu ((ve cac) OR (va cam)) luc ((va thanh) OR (va tinh)) vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ma hoa. hieu ((ve cac) or (va cam)) luc ((va thanh) OR (va tinh)) vi cua vat".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoa. hieu ((ve cac) or (va cam)) luc ((va thanh) OR (va tinh)) vi cua vat*.