Perhaps you should try some spelling variations:
tay dang » tay dong, tay lang, tay tang
tay dung » xay dung, tac dung, tay nung
tu sach » thu sach, su sach, te sach
va lanh » va lang, va danh, va anh
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
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: tu sach ((tay dang) or (tay dung)) xa hoi. hieu ve cac tuc ((va lanh) OR (va hanh)) hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tay dang) OR (tay dung)) xa hoi. hieu ve cac tuc ((va lanh) OR (va hanh)) hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tay dang) or (tay dung)) xa hoi. hieu ve cac tuc ((va lanh) OR (va hanh)) hai cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tay dang) or (tay dung)) xa hoi. hieu ve cac tuc ((va lanh) OR (va hanh)) hai cua te*.