Perhaps you should try some spelling variations:
doan manh » doan minh, hoang manh, tran manh
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
van manh » van minh, van anh, van hanh
tu sach » thu sach, su sach, te sach
so viet » hoc viet
y nang » ky nang, ly nang, v nang
tai so » tai sao, dai so, tai co
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: tu sach y nang x hoi. hieu van nam thuc ((((van manh) or (suc manh))) or (doan manh)) tai so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van nam thuc ((((van manh) OR (suc manh))) OR (doan manh)) tai so viet.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van nam thuc ((((van manh) or (suc manh))) or (doan manh)) tai so viet*.