Perhaps you should try some spelling variations:
dien sach » dien anh
qua trong » quan trong, qua trinh, qua song
hoc dien » hoc hien, hoc vien, hoc dieu
mang qua » mang cua, mang vua, nang quan
cong sat » cong suat, cong hat, cong nhat
cong san » cong tac
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 dien sach - cach mang qua trong ((cong sat) or (cong san)) phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc dien sach - cach mang qua trong ((cong sat) OR (cong san)) phan lap*.