Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
dang xa » dang xay, lang xa, dang ha
nam tuc » nam thuc, nam truc, nam tu
va hanh » va thanh, va danh, ban hanh
y dang » ky dang, 2 dang, _ dang
cua tu » cua tuc, cua su, cua cu

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 y dang xa hoi. hieu van nam tuc ((va hanh) or (van hanh)) tai ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y dang xa hoi. hieu van nam tuc ((va hanh) OR (van hanh)) tai ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y dang xa hoi. hieu van nam tuc ((va hanh) or (van hanh)) tai ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: toc sach y dang xa hoi. hieu van nam tuc ((va hanh) or (van hanh)) tai ((cua te) OR (cua tu))*.