Perhaps you should try some spelling variations:
thong xuan » thong quan, thong quang, thong cua
thong luan » thong quan, tong luan, thong quang
tinh quan » tinh quang, trinh quan, tin quan
hieu soat » hieu suat, hieu hoat, hieu luat
kien soat » kiem soat, bien soan, kien hoa
van hieu » cao hieu
van kien » van tien, van hien, van chien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh quan luan van hieu soat ) or ( trinh ((thong xuan) OR (thong luan)) van kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quan luan van hieu soat ) OR ( trinh ((thong xuan) OR (thong luan)) van kien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh quan luan van hieu soat ) or ( trinh ((thong xuan) OR (thong luan)) van kien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh quan luan van hieu soat ) or ( trinh ((thong xuan) OR (thong luan)) van kien soat ))*.