Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thuoc sac » thuoc dac, thuoc sai, thuoc san
va tham » van tham, va cham, va thanh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
goc va » hoc va, doc va, uoc va
loc va » hoc va, luc va
di cua » dai cua, doi cua, de cua
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: ((thuoc sac) OR (thuoc sach)) ky nang x hoi. lieu va tham ((goc va) or (loc va)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sac) OR (thuoc sach)) ky nang x hoi. lieu va tham ((goc va) OR (loc va)) hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sac) OR (thuoc sach)) ky nang x hoi. lieu va tham ((goc va) or (loc va)) hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sac) OR (thuoc sach)) ky nang x hoi. lieu va tham ((goc va) or (loc va)) hanh di cua tre*.