Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thu sach » thuat sach, thuoc sach, thu hoach
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
tu sach » su sach, te sach, tu cach
hieu va » hieu qua
hang xa » hoang xa, hang va, hang ca
ty hang » ly hang, ty xang, thi hang
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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) or (thu sach)) ty hang xa hoi. ((hieu va) or (lieu va)) nam thuc van hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty hang xa hoi. ((hieu va) OR (lieu va)) nam thuc van hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty hang xa hoi. ((hieu va) or (lieu va)) nam thuc van hanh vi cua tu*.