Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
van chat » cao chat
vu nang » vuc nang, va nang, vu dang
va chat » va phat, cao chat, hoa chat
dan dai » dat dai, can dai, dan dat
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau
x hoi » xa hoi, o hoi, x ho

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) OR (doc sach)) vu nang x hoi. lieu ((va chat) or (van chat)) xuc va dan dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) vu nang x hoi. lieu ((va chat) OR (van chat)) xuc va dan dai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) vu nang x hoi. lieu ((va chat) or (van chat)) xuc va dan dai cua tre*".