Perhaps you should try some spelling variations:
phien nam » hien nay, phien ban, vien nam
trung hoc » trung quoc
hien nam » hien nay, vien nam, mien nam
canh tac » canh tay, canh giac, cong tac
luc viet » luoc viet, tuc viet, duc viet
danh tac » danh bac, doanh tai, danh thuc
vung hoc » dung hoc, vung moc, quang hoc
tac nang » tac vang, tai nang, tap nang
tac van » tac vang, cac van, tac va
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: (((( danh tac ((vung hoc) OR (trung hoc)) viet nam ) or ((( danh tac nang luc viet nam ) or ( canh tac nang luc viet nam ))))) or ( danh tac van hoc ((hien nam) or (phien nam)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( danh tac ((vung hoc) OR (trung hoc)) viet nam ) OR ((( danh tac nang luc viet nam ) OR ( canh tac nang luc viet nam ))))) OR ( danh tac van hoc ((hien nam) OR (phien nam)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( danh tac ((vung hoc) OR (trung hoc)) viet nam ) or ((( danh tac nang luc viet nam ) or ( canh tac nang luc viet nam ))))) or ( danh tac van hoc ((hien nam) or (phien nam)) ))".
• Adding a wildcard symbol may retrieve word variants: (((( danh tac ((vung hoc) OR (trung hoc)) viet nam ) or ((( danh tac nang luc viet nam ) or ( canh tac nang luc viet nam ))))) or ( danh tac van hoc ((hien nam) or (phien nam)) ))*.