Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
quoc quan » qua quan, luc quan, hoc quan
cam quoc » cac quoc, cao quoc, nam quoc
hieu va » lieu va, hieu qua
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
anh di » danh di, xanh di, anh du
tu sac » tu sach, tu cac, tu san
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o hoa

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 nang ((o hoi) or (o hoc)). hieu va cam quoc quan ((anh di) OR (anh d)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((o hoi) OR (o hoc)). hieu va cam quoc quan ((anh di) OR (anh d)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((o hoi) or (o hoc)). hieu va cam quoc quan ((anh di) OR (anh d)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((o hoi) or (o hoc)). hieu va cam quoc quan ((anh di) OR (anh d)) cua triet*.