Perhaps you should try some spelling variations:
tran manh » tran minh, tran thanh, tran van
hieu van » hieu va, thien van, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
dan manh » dang manh, doan manh, van manh
hoc viet » hoc hien
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
vai hoc » van hoc, dai hoc, bai hoc
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 ky nang x hoi. ((hieu van) OR (lieu va)) nam thuc ((dan manh) or (tran manh)) vai hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu van) OR (lieu va)) nam thuc ((dan manh) OR (tran manh)) vai hoc viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu van) OR (lieu va)) nam thuc ((dan manh) or (tran manh)) vai hoc viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((hieu van) OR (lieu va)) nam thuc ((dan manh) or (tran manh)) vai hoc viet*.