Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, cuoc cach, cuon sach
hoc sach » hoc sinh, hoc cac, hoc anh
va cham » va chat, va tham
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
nang o » nang co, nang ho, nang ro
di cua » dai cua, doi cua, de cua
va cam » va cac, va cao, va cai
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: ((nuoc sach) or (hoc sach)) cam nang o hoi. hieu ((va cam) OR (va cham)) luc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((nuoc sach) OR (hoc sach)) cam nang o hoi. hieu ((va cam) OR (va cham)) luc va hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((nuoc sach) or (hoc sach)) cam nang o hoi. hieu ((va cam) OR (va cham)) luc va hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: ((nuoc sach) or (hoc sach)) cam nang o hoi. hieu ((va cam) OR (va cham)) luc va hanh di cua tre*.