Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
ky trong » ly trong, ke trong, cay trong
trong ha » trong nha, trong hai, trong hao
va hanh » van hanh, va thanh, va danh
cac duc » cac du, cao duc, cac dac
tu cach » tu cac
hieu ve » hieu va
ha hoi » hoa hoi, ha noi, xa hoi
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thuoc sach)) ky trong ha hoi. ((hieu ve) OR (hieu van)) cac duc va hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thuoc sach)) ky trong ha hoi. ((hieu ve) OR (hieu van)) cac duc va hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thuoc sach)) ky trong ha hoi. ((hieu ve) OR (hieu van)) cac duc va hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thuoc sach)) ky trong ha hoi. ((hieu ve) OR (hieu van)) cac duc va hanh vi cua vat*.