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