Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
tang hoa » hang hoa, tang ha, tang ho
nam thuc » nam thuoc, am thuc, nam tu
hanh ve » hanh vi, hanh va, hanh kem
hieu ve » hieu va, hieu van
sach ky » sac ky, sach ty, sach kem
hoa hoi » khoa hoi, hoa hoc, hoa doi
su viet » so viet
ve su » va su

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) or (sach y)) tang hoa hoi. hieu ve ((nam thuc) or (nam thu)) vat hanh ve su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) tang hoa hoi. hieu ve ((nam thuc) OR (nam thu)) vat hanh ve su viet.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) tang hoa hoi. hieu ve ((nam thuc) or (nam thu)) vat hanh ve su viet*.