Perhaps you should try some spelling variations:
va thieu » va thiet, va hieu, va tieu
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
cam thuc » am thuc, nam thuc, cam thu
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
so sach » so sanh, bo sach, co sach
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
su sach » vu sach
y lang » o lang, _ lang, tay lang
vai va » mai va, dai va, hai va

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) OR (so sach))) or (vu bach)) y lang xa hoi. hieu van cam thuc va hanh vai va thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((su sach) OR (so sach))) OR (vu bach)) y lang xa hoi. hieu van cam thuc va hanh vai va thieu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((su sach) OR (so sach))) or (vu bach)) y lang xa hoi. hieu van cam thuc va hanh vai va thieu*".