Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
vai cua » dai cua, hai cua, lai cua
anh vai » anh va, anh bai, anh van
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
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)) ly nang x hoi. hieu ve ((cau luc) or (cam xuc)) tuan anh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ly nang x hoi. hieu ve ((cau luc) OR (cam xuc)) tuan anh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ly nang x hoi. hieu ve ((cau luc) or (cam xuc)) tuan anh vai cua tre*".