Perhaps you should try some spelling variations:
nguoi sach » nguoi san, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
den cuu » dinh cuu, dien cuc, dien cua
dan den » ban den, van den, dan dung
cau luc » cau truc, cau phuc
cam luc » cam xuc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
nang o » nang co, nang ho, nang ro
va dan » ca dan, va dao, va dau
v nang » va nang, vu nang, van nang
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: ((hoc sach) or (nguoi sach)) v nang o hoc. hieu va ((cam luc) or (cau luc)) va dan den cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (nguoi sach)) v nang o hoc. hieu va ((cam luc) OR (cau luc)) va dan den cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (nguoi sach)) v nang o hoc. hieu va ((cam luc) or (cau luc)) va dan den cuu tre*.