Perhaps you should try some spelling variations:
nam truc » nam truoc, nam thuc, nam trung
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
hanh di » hanh vi, hanh de, hang di
hieu ve » hieu va, hieu van
di cua » dai cua, doi cua, de cua
cua te » cua tu

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 y ((nang xa) or (nang x)) hoi. hieu ve ((nam truc) or (cau truc)) van hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang x)) hoi. hieu ve ((nam truc) OR (cau truc)) van hanh di cua te.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (nang x)) hoi. hieu ve ((nam truc) or (cau truc)) van hanh di cua te*.