Perhaps you should try some spelling variations:
chat loc » chat hoc, chat doc, chat long
dang xay » dang van
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
tu sach » thu sach, su sach, te sach
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
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 y ((dang xay) or (van xay)) hoi. hieu va chat loc ((va hanh) OR (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((dang xay) OR (van xay)) hoi. hieu va chat loc ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((dang xay) or (van xay)) hoi. hieu va chat loc ((va hanh) OR (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((dang xay) or (van xay)) hoi. hieu va chat loc ((va hanh) OR (va danh)) vi cua tre*.