Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van ban
vien cac » vien bach, vien dai, vien da
sach tu » sach thu, cach tu, sach ty
cac xuc » cam xuc, cac nuoc, chat xuc
tu nang » tru nang, tu nong, tu nano
van anh » van thanh, tuan anh, van minh
dao cua » dai cua, day cua, dan cua
ma hoi » mai hoi, xa hoi, me hoi
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: toc sach tu nang ((ma hoi) or (ma hoa)). hieu vien cac xuc ((van hanh) OR (van anh)) dao cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nang ((ma hoi) OR (ma hoa)). hieu vien cac xuc ((van hanh) OR (van anh)) dao cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu nang ((ma hoi) or (ma hoa)). hieu vien cac xuc ((van hanh) OR (van anh)) dao cua tu".
• Adding a wildcard symbol may retrieve word variants: toc sach tu nang ((ma hoi) or (ma hoa)). hieu vien cac xuc ((van hanh) OR (van anh)) dao cua tu*.