Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang thai » dang thi, dang hai, dang khai
toc sach » hoc sach, doc sach, nuoc sach
cam truc » cau truc, nam truc, lam truoc
thai cua » than cua, tai cuc, tri cua
dang xay » dang van, van xay
va dang » van dang, va nang, va lang
truc va » thuc va, thuc vat, trung va
hieu va » hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
ty dang » ty xang, ky dang, ty hang
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) or (thuoc sach)) ty dang xay hoi. ((hieu va) OR (lieu va)) cam truc va dang thai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) ty dang xay hoi. ((hieu va) OR (lieu va)) cam truc va dang thai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (thuoc sach)) ty dang xay hoi. ((hieu va) OR (lieu va)) cam truc va dang thai cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thuoc sach)) ty dang xay hoi. ((hieu va) OR (lieu va)) cam truc va dang thai cua te*.