Perhaps you should try some spelling variations:
tu tieng » luc tieng, tu tuong, tu trong
thu sach » thuat sach, thuoc sach, thu hoach
luan va » luan van, luat va
tuan va » toan va, quan va, than va
xuc van » duc van, luc van, vuc van
tu sach » su sach, te sach, tu cach
vu nang » vuc nang, va nang, vu dang
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho

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)) vu nang x hoi. hieu va cam xuc van ((tuan va) OR (luan va)) tu tieng~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) vu nang x hoi. hieu va cam xuc van ((tuan va) OR (luan va)) tu tieng.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) vu nang x hoi. hieu va cam xuc van ((tuan va) OR (luan va)) tu tieng".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) vu nang x hoi. hieu va cam xuc van ((tuan va) OR (luan va)) tu tieng*.