Perhaps you should try some spelling variations:
danh tac » danh bac, doanh tai, danh thuc
tac vang » cac van, tac dung, tac dong
vang hoc » van hoc, nang hoc, vung hoc
hien nay » hien dai
vien nam » vien dai, van nam, vien da
canh tac » canh tay, canh giac, cong tac
hoc viet » hoc hien

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 vang hoc ((hien nay) or (vien nam)) ) or ( canh tac vang hoc viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( danh tac vang hoc ((hien nay) OR (vien nam)) ) OR ( canh tac vang hoc viet nam )).
• Adding a wildcard symbol may retrieve word variants: (( danh tac vang hoc ((hien nay) or (vien nam)) ) or ( canh tac vang hoc viet nam ))*.