Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
hieu le » hieu ve, hieu he, hieu ly
hanh va » hang va, hanh vi
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
va hoa » van hoa, va hoc
le nam » ly nam, he nam, le na
me hoi » le hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sach ty)) dang ((me hoi) or (ma hoa)). hieu le nam thuc van hanh va hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) dang ((me hoi) OR (ma hoa)). hieu le nam thuc van hanh va hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) dang ((me hoi) or (ma hoa)). hieu le nam thuc van hanh va hoa viet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach ty)) dang ((me hoi) or (ma hoa)). hieu le nam thuc van hanh va hoa viet*.