Perhaps you should try some spelling variations:
sach tham » sach nha
cua viet » ca viet, hoa viet, cua vat
nang lai » mang lai, nang cai, nang hai
su triet » su viet, su tien, ve triet
nang tai » hang tai, tang tai, sang tai
dao vai » dao van, dao va, dao bai
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
co duc » co duoc, cao duc, do duc
va dao » ca dao
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: tu sach tham ((nang lai) OR (nang tai)) roi. hieu va co duc va dao vai ((su triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tham ((nang lai) OR (nang tai)) roi. hieu va co duc va dao vai ((su triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tham ((nang lai) OR (nang tai)) roi. hieu va co duc va dao vai ((su triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach tham ((nang lai) OR (nang tai)) roi. hieu va co duc va dao vai ((su triet) or (cua viet))*.