Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
danh tai » doanh tai, dinh tai, hanh tai
thuc va » thuc vat, thuc dan, thuc day
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » hieu qua
tai cua » thai cua, tai cuc, tri cua
sach ky » sac ky, sach y, sach ty
truc va » thuc vat, trung va
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: toc sach ky dang xay hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc va)) danh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. ((hieu va) OR (lieu va)) cam ((truc va) OR (thuc va)) danh tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc va)) danh tai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc va)) danh tai cua te*.