Perhaps you should try some spelling variations:
van thanh » ban thanh
cua viet » ca viet, hoa viet, cua vat
va triet » va thiet, va trien, ve triet
van tuan » van quan, van ban, anh tuan
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
cam luc » cam xuc, cau luc
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang o hai. hieu ve cam luc ((van thanh) OR (van tuan)) keo ((va triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hai. hieu ve cam luc ((van thanh) OR (van tuan)) keo ((va triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang o hai. hieu ve cam luc ((van thanh) OR (van tuan)) keo ((va triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hai. hieu ve cam luc ((van thanh) OR (van tuan)) keo ((va triet) or (cua viet))*.