Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
te sach » toc sach
ty mang » ty xang, ty hang, tin mang
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
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 (te sach))) or (thu hoach)) ty mang xa hoi. hieu va cam tuc va hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (te sach))) OR (thu hoach)) ty mang xa hoi. hieu va cam tuc va hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (te sach))) or (thu hoach)) ty mang xa hoi. hieu va cam tuc va hanh vi cua tu*.