Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh gia » danh gia, thanh gian, hinh giao
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
gia cua » gian cua, giau cua, gia cuc
duc van » duc va, duc tan, duc manh
vien da » vien dai, hien dai
tu sach » thu sach, su sach, te sach
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai
o hoc » co hoc, mo hoc, so hoc

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 nang ((o hoc) or (o hai)). hieu ((ve cac) or (vien da)) duc van hanh gia cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoc) OR (o hai)). hieu ((ve cac) OR (vien da)) duc van hanh gia cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoc) or (o hai)). hieu ((ve cac) or (vien da)) duc van hanh gia cua triet*.