Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
nang dai » nang dau, nang tai, lang dai
dai khoa » da khoa, tai khoa, dac khoa
cac luc » cau luc, coc luc, cac nuoc
day cua » dai cua
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ky) OR (sach ty)) nang dai khoa. hieu ve cac luc ((va hanh) or (va thanh)) day cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ky) OR (sach ty)) nang dai khoa. hieu ve cac luc ((va hanh) OR (va thanh)) day cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ky) OR (sach ty)) nang dai khoa. hieu ve cac luc ((va hanh) or (va thanh)) day cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sach ky) OR (sach ty)) nang dai khoa. hieu ve cac luc ((va hanh) or (va thanh)) day cua tre*.