Perhaps you should try some spelling variations:
trinh phan » trinh han, trinh quan, thanh phan
cong tinh » cong vinh, long tinh, cong thanh
hoc viet » hoc hien
phan ran » phan van, phan lan, phan tan
chat lan » chat ban, chat ran, chat van
yang va » bang va, dang va, sang va
cac nam » bac nam, cac cam, cac ham
cac cac » cac cach, ca cac, cac bac
nam co » nam cao, nam bo, nam so
ran va » rang va, ban va, dan va
cac co » cac cong
lan va » luan va, lanh va, lan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( cong trinh giao ((yang va) OR (hang va)) cac nam co hoc viet nam ) or ((( cong trinh phan ran va cac cac co hoc viet nam ) or ( cong tinh chat lan va cac cac co hoc viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh giao ((yang va) OR (hang va)) cac nam co hoc viet nam ) OR ((( cong trinh phan ran va cac cac co hoc viet nam ) OR ( cong tinh chat lan va cac cac co hoc viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh giao ((yang va) OR (hang va)) cac nam co hoc viet nam ) or ((( cong trinh phan ran va cac cac co hoc viet nam ) or ( cong tinh chat lan va cac cac co hoc viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh giao ((yang va) OR (hang va)) cac nam co hoc viet nam ) or ((( cong trinh phan ran va cac cac co hoc viet nam ) or ( cong tinh chat lan va cac cac co hoc viet nam ))))*.