Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
hoc sach » hoc sinh, hoc cac, hoc anh
hieu san » hieu van, chieu sang, hieu suat
hieu sau » hieu su, hieu suat, tieu su
vat hanh » vat thanh, van hanh, va hanh
tu cach » tu cac
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
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 (hoc sach)) ky nang xa hoi. ((hieu san) OR (hieu sau)) nham thuc vat hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (hoc sach)) ky nang xa hoi. ((hieu san) OR (hieu sau)) nham thuc vat hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (hoc sach)) ky nang xa hoi. ((hieu san) OR (hieu sau)) nham thuc vat hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (hoc sach)) ky nang xa hoi. ((hieu san) OR (hieu sau)) nham thuc vat hanh vi cua tre*.