Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dien cuc » dien tu, dieu cua, vien cac
doc sach » toc sach, nuoc sach, dac sac
van dinh » van minh, van dich, va dinh
va danh » va dinh, va dan, va hanh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
vu nang » vuc nang, va nang, vu dang
cuc tre » duc tre, cua tre, cuu tre
va cam » va cham, va cac, va cao
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (doc sach)) vu nang o hoc. hieu va cam luc ((va danh) OR (van dinh)) dien cuc tre~.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (doc sach)) vu nang o hoc. hieu va cam luc ((va danh) or (van dinh)) dien cuc tre*.