Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve cac » va cac, vien cac
cac lo » cac lop, cac co, cac bo
lo va » lo van, lao va, ly va

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 ve cac lo va ((hanh vai) OR (hanh tai)) 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 ve cac lo va ((hanh vai) OR (hanh tai)) 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 ve cac lo va ((hanh vai) OR (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang xa hoi. hieu ve cac lo va ((hanh vai) OR (hanh tai)) cua tre*.