Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
hanh sai » hanh san, hanh tai, danh sai
cham tuc » nham thuc, pham thuc, tham thuc
van cham » van chat, van tham, va cham
hoc sach » hoc sinh, hoc cac, hoc anh
nang xa » lang xa, nang ma, mang xa
va hanh » van hanh, va thanh, va danh
sai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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 (hoc sach)) ky ((nang xa) or (nang x)) hoi. hieu van cham tuc va hanh sai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky ((nang xa) OR (nang x)) hoi. hieu van cham tuc va hanh sai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ky ((nang xa) or (nang x)) hoi. hieu van cham tuc va hanh sai cua tre*.