Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh duc » minh duc, ninh duc, tinh duc
duc cuu » duc suu
va dinh » van dinh, va kinh, va tinh
cam luc » cam xuc, cau luc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
mang xa » lang xa, mang may, dang xay

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 ((mang xa) or (nang ma)) hoi. hieu va ((cam luc) or (cau truc)) va dinh duc cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((mang xa) OR (nang ma)) hoi. hieu va ((cam luc) OR (cau truc)) va dinh duc cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y ((mang xa) or (nang ma)) hoi. hieu va ((cam luc) or (cau truc)) va dinh duc cuu tre*.