Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh lap » dinh lam, trinh lap, dinh lang
van cam » van nam, van lam, van dam
lap cua » lai cua, tap cua, lam cua
va dinh » van dinh, va kinh, va tinh
van cau » van dau, van hau, van chat
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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) OR (toc sach)) ky tang ma hoi. thien ((van cam) or (van cau)) duc va dinh lap cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky tang ma hoi. thien ((van cam) OR (van cau)) duc va dinh lap cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky tang ma hoi. thien ((van cam) or (van cau)) duc va dinh lap cua tre*".