Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec bach » vien bach, viec ban, viec bao
hanh vai » hanh vi, hanh tai, hanh van
bach duc » bach tuoc, sach duoc, thach duc
nang dai » nang dau, nang tai, lang dai
dai khoa » da khoa, tai khoa, dac khoa
hanh va » hang va, hanh vi
tu sach » thu sach, su sach, tu cach
tu nang » tru nang, tu nong, tu nano
te sach » toc sach

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)) tu nang dai khoa. hieu viec bach duc va ((hanh vai) or (hanh va)) hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) tu nang dai khoa. hieu viec bach duc va ((hanh vai) OR (hanh va)) hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) tu nang dai khoa. hieu viec bach duc va ((hanh vai) or (hanh va)) hoa viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) tu nang dai khoa. hieu viec bach duc va ((hanh vai) or (hanh va)) hoa viet*.