Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
chat duc » chat xuc, chat doc, chet duoc
lua tren » dua tren, la tren, quan tren
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
va dinh » van dinh, va kinh, va tinh
dinh vi » dinh ve, dinh viet, dinh tri
nang o » nang co, nang ho, nang ro
vi lua » vi luu
o hoi » co hoi, o hoc, o hai

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: ((te sach) OR (toc sach)) ky nang o hoi. hieu va chat duc va dinh vi lua tren~.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang o hoi. hieu va chat duc va dinh vi lua tren*.