Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
hieu van » hieu va, thien van, lieu va
van hac » van hoc, van ha, van hai
hac dat » hoc dat, tac dat, hoach dat
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
ma hoi » mai hoi, xa hoi, me hoi
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuoc sach)) ky nang ((ma hoi) or (ma hoa)). hieu van hac dat va hanh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang ((ma hoi) OR (ma hoa)). hieu van hac dat va hanh di cua vat.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) ky nang ((ma hoi) or (ma hoa)). hieu van hac dat va hanh di cua vat*.