Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
doc sach » hoc sach, nuoc sach, dac sac
tay lang » tai lang, tay tang, tay quang
san hanh » san thanh, ban hanh, van hanh
cham cua » chat cua, cham cuu, ham cua
van cham » van chat, van tham, va cham
hanh di » hanh vi, hanh de, hang di
cua san » cua ban, cua dan, ca san
cua tre » cua te, cuu tre, cua triet
o lang » hoa lang, hoi lang
di cua » dai cua, doi cua, de cua

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)) ((tay lang) or (o lang)) xa hoi. hieu van cham cua san hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ((tay lang) OR (o lang)) xa hoi. hieu van cham cua san hanh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ((tay lang) or (o lang)) xa hoi. hieu van cham cua san hanh di cua tre*".