Perhaps you should try some spelling variations:
"quyen trinh." » "truyen trinh." (Expand Search), "nguyen trinh." (Expand Search), "quy trinh." (Expand Search)
"quan trinh." » "qua trinh." (Expand Search), "quan tinh." (Expand Search), "quan tri." (Expand Search), "quan trih." (Expand Search), "quan tranh." (Expand Search), "quan trenh." (Expand Search)
"xuan trinh." » "xuan tinh." (Expand Search), "qua trinh." (Expand Search), "xuan thanh." (Expand Search)
"quan trin." » "quan tri." (Expand Search), "quan tran." (Expand Search), "quan tren." (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((((("quan trinh.") OR ("quyen trinh."))) OR ("quan trin."))) OR ("xuan trinh."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"quan trinh.\") OR (\"quyen trinh.\"))) OR (\"quan trin.\"))) OR (\"xuan trinh.\"))".
• Removing quotes may allow a broader search: (((((( quan trinh. ) OR ( quyen trinh. ))) OR ( quan trin. ))) OR ( xuan trinh. )).
• Adding a wildcard symbol may retrieve word variants: (((((("quan trinh.") OR ("quyen trinh."))) OR ("quan trin."))) OR ("xuan trinh."))*.