Perhaps you should try some spelling variations:
trinh phan » trinh han, trinh quan, thanh phan
giao yang » miao yang, gian lang, gia tang
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 » hang va, bang va, dang 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 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 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 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 ))))*.