Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
luoc van » luoc can, luoc va, luot van
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
luc van » luu van, duc van, luc va
ve cam » ve cham, ve cac, va cam

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 tang xa hoi. hieu ve cam ((luc van) OR (luoc van)) hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang xa hoi. hieu ve cam ((luc van) OR (luoc van)) hanh vi ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang xa hoi. hieu ve cam ((luc van) OR (luoc van)) hanh vi ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang xa hoi. hieu ve cam ((luc van) OR (luoc van)) hanh vi ((cua tre) or (cau tren))*.