Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang cau » nang cao, hang cau, nang dau
cac nuoc » cap nuoc, hoc nuoc, cua nuoc
hanh lai » hanh lam, hanh tai, thanh lap
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sac ky)) nang cau hoi. hieu ve ((cac nuoc) or (dat nuoc)) va hanh lai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang cau hoi. hieu ve ((cac nuoc) OR (dat nuoc)) va hanh lai cua triet.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang cau hoi. hieu ve ((cac nuoc) or (dat nuoc)) va hanh lai cua triet*.