Perhaps you should try some spelling variations:
van chat » cao chat
danh dai » danh dau, danh di, danh sai
thu sach » thuat sach, thuoc sach, thu hoach
thuc dan » thuc hanh, hoc dan, thuc vat
hieu van » hieu va, thien van, lieu va
thuc day » thuc vat
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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 (thu sach)) ky nang xa hoi. hieu van chat ((thuc day) or (thuc dan)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu van chat ((thuc day) OR (thuc dan)) danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang xa hoi. hieu van chat ((thuc day) or (thuc dan)) danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu van chat ((thuc day) or (thuc dan)) danh dai cua tre*.