Perhaps you should try some spelling variations:
dieu cua » dieu tra
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ra bang » va bang, ba bang, cao bang
xa bang » va bang, ba bang, xa ban
nang ma » tang ma, sang ma, nang cao
vien da » vien dai
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
hien » bien, tien, dien

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 ty nang ma hoi. hieu ((vien da) or (hien dai)) tac ((xa bang) OR (ra bang)) dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ma hoi. hieu ((vien da) OR (hien dai)) tac ((xa bang) OR (ra bang)) dieu cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ma hoi. hieu ((vien da) or (hien dai)) tac ((xa bang) OR (ra bang)) dieu cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ma hoi. hieu ((vien da) or (hien dai)) tac ((xa bang) OR (ra bang)) dieu cua tre*.