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