Perhaps you should try some spelling variations:
canh tac » canh giac, cong tac, anh ta
tac vang » cac van, tac dung, tac dong
vang hoc » nang hoc, vung hoc, mang hoc
tac bang » cac bang, tao bang, thai bang
bang hoc » nang hoc, mang hoc, quang hoc
canh tay » thanh tay, anh ta, ban tay
tay bang » tay ban, tao bang, tay lang
hien nam » phien nam, hien nay, vien nam
dan cach » dan cac, dan canh, nhan cach
cach van » cac van, bach van, canh van
tai van » thai van, thi van, tai san
van hoc » van hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( canh tac vang hoc viet nam ) or ((( canh tac bang hoc viet nam ) OR ( canh tay bang hoc viet nam ))))) or ((( doanh tai van hoc hien nam ) or ( dan cach van hoc hien nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( canh tac vang hoc viet nam ) OR ((( canh tac bang hoc viet nam ) OR ( canh tay bang hoc viet nam ))))) OR ((( doanh tai van hoc hien nam ) OR ( dan cach van hoc hien nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( canh tac vang hoc viet nam ) or ((( canh tac bang hoc viet nam ) OR ( canh tay bang hoc viet nam ))))) or ((( doanh tai van hoc hien nam ) or ( dan cach van hoc hien nam ))))".
• Adding a wildcard symbol may retrieve word variants: (((( canh tac vang hoc viet nam ) or ((( canh tac bang hoc viet nam ) OR ( canh tay bang hoc viet nam ))))) or ((( doanh tai van hoc hien nam ) or ( dan cach van hoc hien nam ))))*.