Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
danh dau » lanh dao, hang dau, danh tu
nhan loc » nhan luc, nhan hoc, nhan loai
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
te sach » toc sach
hieu ve » hieu van
tang ma » tang van
loc va » hoc va, luc va
dau su » dau tu, dan su, da su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((tang ma) OR (mang may)) hoi. ((hieu ve) or (hieu va)) nhan loc va danh dau su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((tang ma) OR (mang may)) hoi. ((hieu ve) OR (hieu va)) nhan loc va danh dau su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((tang ma) OR (mang may)) hoi. ((hieu ve) or (hieu va)) nhan loc va danh dau su triet".
• Adding a wildcard symbol may retrieve word variants: te sach y ((tang ma) OR (mang may)) hoi. ((hieu ve) or (hieu va)) nhan loc va danh dau su triet*.