Perhaps you should try some spelling variations:
minh giao » trinh giao, tinh gia, dinh gia
canh giac » danh gia, anh giao, canh tac
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
tu sai » tu bai, tu san, tu cai
lo van » le van, vo van, so van
sai ky » sac ky
ve cac » va cac, vien cac
cac lo » cac lop, cac co, cac bo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((nang xa) OR (nang x)) hoi. hieu ve cac lo van ((canh giac) or (minh giao)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang xa) OR (nang x)) hoi. hieu ve cac lo van ((canh giac) OR (minh giao)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((nang xa) OR (nang x)) hoi. hieu ve cac lo van ((canh giac) or (minh giao)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang xa) OR (nang x)) hoi. hieu ve cac lo van ((canh giac) or (minh giao)) cua tre*.