Perhaps you should try some spelling variations:
bo sach » co sach, hoc sach
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa
de cua » le cua, te cua, dieu cua
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ky nang ((o hoi) or (xa hoi)). lieu ((van nam) or (ha nam)) tuc va danh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ky nang ((o hoi) OR (xa hoi)). lieu ((van nam) OR (ha nam)) tuc va danh de cua tre.
• Adding a wildcard symbol may retrieve word variants: bo sach ky nang ((o hoi) or (xa hoi)). lieu ((van nam) or (ha nam)) tuc va danh de cua tre*.