Perhaps you should try some spelling variations:
luan hieu » luan tieu, luan dieu, luan thiet
pho gian » thoi gian, cho giang, ho gia
hieu cua » hieu qua, dieu cua, bieu cua
dan luan » doanh luan, dung luan, tang luan
khoe dan » khoe ban, khoa dang, khoe dinh
hieu tra » dieu tra, hiep tran, chieu tro
tien thu » tieu thu, kien thuc, trien thi
van tien » toan tien, van hieu, van tuan
pho giao » cho giao, phong giao, phat giao
cap cua » cap cuu, ca cua, cau cua
cua tap » cua tam, cua phap
tap cua » tap quan, tiep cua
cho cay » cho cac, cho vay, cho can

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((pho gian) OR (pho giao)) van tien thu ) or ((((( pho cap cua tap cua ) or ( cho cay ((cua dieu) or (va dieu)) cua ))) or ((( khoe dan luan hieu cua ) or ( khoe dan luan hieu tra ))))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((pho gian) OR (pho giao)) van tien thu ) OR ((((( pho cap cua tap cua ) OR ( cho cay ((cua dieu) OR (va dieu)) cua ))) OR ((( khoe dan luan hieu cua ) OR ( khoe dan luan hieu tra ))))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((pho gian) OR (pho giao)) van tien thu ) or ((((( pho cap cua tap cua ) or ( cho cay ((cua dieu) or (va dieu)) cua ))) or ((( khoe dan luan hieu cua ) or ( khoe dan luan hieu tra ))))))*".