Perhaps you should try some spelling variations:
vien dai » hien dai
lua tre » cua tre, dua tren, luat tri
va doan » va doanh, van doan, va dan
te sach » toc sach
luy tre » luyen tre
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
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: te sach y nang x hoi. hieu ((ve cac) or (vien dai)) luc va doan va ((lua tre) or (luy tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang x hoi. hieu ((ve cac) OR (vien dai)) luc va doan va ((lua tre) OR (luy tre)).
• Adding a wildcard symbol may retrieve word variants: te sach y nang x hoi. hieu ((ve cac) or (vien dai)) luc va doan va ((lua tre) or (luy tre))*.