Perhaps you should try some spelling variations:
tu tieng » luc tieng, tu tuong, tu trong
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
hieu va » lieu va, hieu qua
xuc van » luc van, xuc ban, thuc van
vuc van » luc van, thuc van, chuc van
duc van » duc va, duc tan, duc manh
tuan ve » tuan le, quan ve, luan ve
va cam » va cham, va cac, va cao
x hoi » xa hoi, o hoi, x ho
ve tu » ve thu, va tu, ve su

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