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
lang xa » lang ha, dang xay, lang van
va hanh » va thanh, va danh, ban hanh
tai cua » thai cua, tai cuc, dai cua
y lang » o lang, _ lang, tay lang
nam tu » nam thu, nam thuc

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