Perhaps you should try some spelling variations:
su sach » so sach, vu sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
nam xuc » nam xua, nam thuc, nam duoc
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
ty nang » ky nang, ty xang, ty hang
di cua » dai cua, doi cua, de 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: su sach ty nang ((o hoi) or (xa hoi)). lieu va ((nam xuc) OR (cam xuc)) va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((o hoi) OR (xa hoi)). lieu va ((nam xuc) OR (cam xuc)) va hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((o hoi) or (xa hoi)). lieu va ((nam xuc) OR (cam xuc)) va hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((o hoi) or (xa hoi)). lieu va ((nam xuc) OR (cam xuc)) va hanh di cua tre*.