Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
cham loc » cham soc, chon loc, hau loc
dang xay » dang van, van xay
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet
y dang » ky dang, 2 dang, _ dang
cham o » cham soc
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: ((tu sach) OR (thu sach)) y dang xay hoi. hieu ve ((cham loc) or (cham o)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y dang xay hoi. hieu ve ((cham loc) OR (cham o)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) y dang xay hoi. hieu ve ((cham loc) or (cham o)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) y dang xay hoi. hieu ve ((cham loc) or (cham o)) va hanh vi cua tre*.