Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
dan vat » dang vat, van vat, dan va
dan vai » dan va, dan tai, den vai
cac tac » cac toc, cac bac, cac dac
hieu va » lieu va, hieu qua
dang ma » dang mau, dang mam, dang mat
hieu ve » hieu van
ky dang » ky nang, ky danh
tac va » tac da, tac xa, tuc va
ma hoi » mai hoi, xa hoi, ma hoa
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: te sach ky dang ma hoi. ((hieu ve) or (hieu va)) cac tac va ((dan vai) OR (dan vat)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ma hoi. ((hieu ve) OR (hieu va)) cac tac va ((dan vai) OR (dan vat)) cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang ma hoi. ((hieu ve) or (hieu va)) cac tac va ((dan vai) OR (dan vat)) cua te*".