Perhaps you should try some spelling variations:
cau luan » cu luan, dau luan, lau luan
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
te sach » toc sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
hanh ve » hanh vi, hanh va, hanh kem
ve cau » ke cau, va cau, ve cac
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((nang xa) or (nang ma)) hoi. hieu ve cau luan van hanh ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang xa) OR (nang ma)) hoi. hieu ve cau luan van hanh ve su triet*.