Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cam thuc » am thuc, nam thuc, cam thu
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hang xa » hoang xa, hang va, hang ca
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty hang xa hoi. ((hieu va) or (hieu van)) cam thuc va hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty hang xa hoi. ((hieu va) OR (hieu van)) cam thuc va hanh vai cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty hang xa hoi. ((hieu va) or (hieu van)) cam thuc va hanh vai cua viet*.