Perhaps you should try some spelling variations:
thanh ve » hanh ve, thanh va, thanh vien
te sach » toc sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
sang ma » tang ma, nang ma, sang tao
hieu vu » hieu va, hieu su, dieu vu
ty sang » ty xang, ty hang, duy sang
ma hoi » mai hoi, xa hoi, ma hoa
soc va » hoc va, loc va, goc va
doc va » duoc va, hoc va, duc va
ve cua » le cua, de cua, te cua
cua su » qua 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 ty sang ma hoi. ((hieu vu) or (hieu ve)) cham ((soc va) OR (doc va)) thanh ve cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty sang ma hoi. ((hieu vu) OR (hieu ve)) cham ((soc va) OR (doc va)) thanh ve cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty sang ma hoi. ((hieu vu) or (hieu ve)) cham ((soc va) OR (doc va)) thanh ve cua su".
• Adding a wildcard symbol may retrieve word variants: te sach ty sang ma hoi. ((hieu vu) or (hieu ve)) cham ((soc va) OR (doc va)) thanh ve cua su*.