Perhaps you should try some spelling variations:
thanh ve » hanh ve, thanh va, thanh vien
thanh vi » hanh vi, thanh va, nhanh vi
suc toan » duc toan, quoc toan, duc tan
su sach » so sach, vu sach
cao suc » cao su, cao duc
hieu ve » hieu va, hieu van
ty hang » ly hang, thi hang, thu hang
ve cao » va cao, ve bao, ve cac
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((ty hang) or (ty xang)) xa hoi. hieu ve cao suc toan ((thanh vi) OR (thanh ve)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty hang) OR (ty xang)) xa hoi. hieu ve cao suc toan ((thanh vi) OR (thanh ve)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty hang) or (ty xang)) xa hoi. hieu ve cao suc toan ((thanh vi) OR (thanh ve)) cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty hang) or (ty xang)) xa hoi. hieu ve cao suc toan ((thanh vi) OR (thanh ve)) cua te*.