Perhaps you should try some spelling variations:
trung long » truong long, trung uong, trong long
hien sach » dien sach, kien sach, thien hach
dua trung » duc trung, cua trung, dua trong
long span » cong san, dong san, nong san
span phan » san phan, san pham, luan phan
dien dan » hien dai, vien dai, gian dan
anh nang » ganh nang, anh bang, anh dang
nang dua » nang du, nang suat, nang quan
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien sach) or (dien dan)) - anh nang dua trung long span phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sach) OR (dien dan)) - anh nang dua trung long span phan lap*.