Perhaps you should try some spelling variations:
cam luoc » cam xuc, tom luoc, cam lo
van hanh » van thanh, ban hanh, van anh
luoc van » luoc can, luoc va, luc van
tu sach » thu sach, su sach, te sach
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
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 ((ke trang) OR (ke toan)) xa hoi. hieu ve cam luoc van hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ke trang) OR (ke toan)) xa hoi. hieu ve cam luoc van hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ke trang) OR (ke toan)) xa hoi. hieu ve cam luoc van hanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ke trang) OR (ke toan)) xa hoi. hieu ve cam luoc van hanh vi ((cua tre) or (cuu tre))*.