Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
dua tren » dung tren
nam xua » nam cua, nam mua, nam luat
nam qua » nam quan, nam cua, nam mua
hanh ve » hanh vi, hanh va, hanh kem
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x hoi. hieu van ((nam xua) OR (nam qua)) ban hanh ve ((dua tren) OR (cua triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x hoi. hieu van ((nam xua) OR (nam qua)) ban hanh ve ((dua tren) or (cua triet))~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x hoi. hieu van ((nam xua) OR (nam qua)) ban hanh ve ((dua tren) or (cua triet))*.