Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
sach thu » sach thue, sach thieu, sach tham
nang tai » tang tai, sang tai, nang cao
danh vai » danh sai, danh va, doanh van
hang tai » hang va, dung tai
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
te sach » toc sach
va cao » va cac, va dao, va bao
va co » vo co

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thu ((nang tai) OR (hang tai)) hoi. hieu ((va cao) or (va co)) duc va danh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu ((nang tai) OR (hang tai)) hoi. hieu ((va cao) OR (va co)) duc va danh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu ((nang tai) OR (hang tai)) hoi. hieu ((va cao) or (va co)) duc va danh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: te sach thu ((nang tai) OR (hang tai)) hoi. hieu ((va cao) or (va co)) duc va danh vai cua viet*.