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 va, hanh tai
nang dai » nang dau, nang tai, lang dai
dai khoa » da khoa, tai khoa, dac khoa
tu sach » thu sach, te sach, tu cach
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
ca viet » va viet, co viet, hoa viet
xuc va » tuc va, luc va, xac va
vai ca » vai cac, vai cua, bai ca

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