Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thuc day » thuc dan
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua
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: ((tu sach) or (thuoc sach)) ky nang x hoi. hieu ve chat ((thuc day) OR (thuc vat)) hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky nang x hoi. hieu ve chat ((thuc day) OR (thuc vat)) hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky nang x hoi. hieu ve chat ((thuc day) OR (thuc vat)) hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky nang x hoi. hieu ve chat ((thuc day) OR (thuc vat)) hanh vi luu tre*.