Perhaps you should try some spelling variations:
dan khanh » dang khanh, van khanh, dat khanh
dan hanh » dang hanh, dan thanh, ban hanh
hieu ve » hieu va, hieu van
nam hoc » nam moc, nam hoi, am hoc
cong xa » cong xay, cong xua, cong ha
ky cong » ke cong, ly cong, khu cong
vai cua » dai cua, hai cua, lai cua
ve nam » he nam, va nam, le nam
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky cong xa hoi. hieu ve nam hoc ((dan hanh) OR (dan khanh)) ((di cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky cong xa hoi. hieu ve nam hoc ((dan hanh) OR (dan khanh)) ((di cua) OR (vai cua)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky cong xa hoi. hieu ve nam hoc ((dan hanh) OR (dan khanh)) ((di cua) or (vai cua)) triet*".