Perhaps you should try some spelling variations:
sach chuc » cach thuc, sach che, sach thu
toc sach » hoc sach, doc sach, thuoc sach
dan dai » dat dai, can dai, dan dat
dai cuu » dai cua, dai huu
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
va cam » va cham, va cao, va cai
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
o hoc » co hoc, mo hoc, so hoc

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 chuc nang o hoc. hieu ((va cam) or (va cac)) luc va dan dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach chuc nang o hoc. hieu ((va cam) OR (va cac)) luc va dan dai cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach chuc nang o hoc. hieu ((va cam) or (va cac)) luc va dan dai cuu tre*.