Perhaps you should try some spelling variations:
dan dinh » dang dinh, doan dinh, van dinh
thuc dan » thuc hanh, hoc dan, thuc vat
tu cach » tu cac
ket cua » ket qua, det cua, keo cua
cua tre » cua te, cuu tre, cua triet
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
va cau » van cau, va cac, va dau
ve cau » ke cau, ve cac, le cau

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 (te sach)) ky tang xa hoi. hieu ((ve cau) OR (va cau)) thuc dan dinh ket cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (te sach)) ky tang xa hoi. hieu ((ve cau) OR (va cau)) thuc dan dinh ket cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (te sach)) ky tang xa hoi. hieu ((ve cau) OR (va cau)) thuc dan dinh ket cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (te sach)) ky tang xa hoi. hieu ((ve cau) OR (va cau)) thuc dan dinh ket cua tre*.