Perhaps you should try some spelling variations:
dang tay » dang xay, dung tay, dan tay
hieu van » hieu va, thien van, lieu va
te sach » toc sach
sach ty » sach y, sach tu, sach thu
ty dang » ty xang, ky dang, ty hang
tay hoi » tay ho, tao hoi, tay thai
dinh vi » dinh ve, dinh viet, dinh tri
luc va » tuc va, loc va
vi cua » vai cua, di cua

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 dang tay hoi. ((hieu van) or (hieu qua)) cam ((luc va) or (duc va)) dinh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty dang tay hoi. ((hieu van) OR (hieu qua)) cam ((luc va) OR (duc va)) dinh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: te sach ty dang tay hoi. ((hieu van) or (hieu qua)) cam ((luc va) or (duc va)) dinh vi cua vat*.