Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac
xuc va » tuc va, luc va, xac 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 ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (duc va)) hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) OR (duc va)) hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (duc va)) hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (duc va)) hanh vai cuu tre*.