Perhaps you should try some spelling variations:
canh giac » danh gia, anh giao, canh tac
ban thuoc » dang thuoc, cay thuoc, nam thuoc
van thuoc » va thuoc, van thuc, van phuoc
phien nam » hien nay, phien ban, vien nam
hoc phien » thuoc phien, hoc nghien, hoc phan
giac van » gian van, giay van, giai van
hien nam » hien nay, vien nam, mien nam
tac vang » cac van, tac dung, tac dong
tac van » cac van, tac va, tac can
van hoc » van hoa
anh ta » anh tu, anh va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((( sang ((tac van) OR (tac vang)) hoc hien nam ) OR ( ((anh ta) OR (anh tuan)) van hoc hien nam ))) OR ((( canh giac van hoc phien nam ) OR ( canh giac ((van thuoc) OR (ban thuoc)) phien nam ))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( sang ((tac van) or (tac vang)) hoc hien nam ) or ( ((anh ta) or (anh tuan)) van hoc hien nam ))) or ((( canh giac van hoc phien nam ) or ( canh giac ((van thuoc) OR (ban thuoc)) phien nam ))))~".
• Adding a wildcard symbol may retrieve word variants: (((( sang ((tac van) or (tac vang)) hoc hien nam ) or ( ((anh ta) or (anh tuan)) van hoc hien nam ))) or ((( canh giac van hoc phien nam ) or ( canh giac ((van thuoc) OR (ban thuoc)) phien nam ))))*.