Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
te sach » toc sach
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
su viet » so viet
vi su » va su, ve su, ki 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 ((lang xa) or (dang xay)) hoi. hieu va cac nuoc va danh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((lang xa) OR (dang xay)) hoi. hieu va cac nuoc va danh vi su viet.
• Adding a wildcard symbol may retrieve word variants: te sach ty ((lang xa) or (dang xay)) hoi. hieu va cac nuoc va danh vi su viet*.