Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thien quan » trien quang, lien quan, thien van
hieu quan » hieu qua, lieu quan, lien quan
dang xay » dang van, van xay
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
nam duc » nam duoc, pham duc, nam thuc
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
ve cau » ke cau, va cau, ve cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky dang xay hoi. ((hieu quan) OR (thien quan)) nam duc va hanh ve cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky dang xay hoi. ((hieu quan) OR (thien quan)) nam duc va hanh ve cau tren".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky dang xay hoi. ((hieu quan) OR (thien quan)) nam duc va hanh ve cau tren*.