Perhaps you should try some spelling variations:
"advanced testing in econometrics / advanced testing in econometrics" » "advanced routing in econometrics / advanced routing in econometrics", "advanced training in econometrics / advanced training in econometrics"
"advanced editing in econometrics / advanced editing in econometrics" » "advanced editions in econometrics / advanced editions in econometrics"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("advanced text in econometrics / advanced text in econometrics") OR ((("advanced testing in econometrics / advanced testing in econometrics") OR ("advanced editing in econometrics / advanced editing in econometrics")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"advanced text in econometrics / advanced text in econometrics\") or (((\"advanced testing in econometrics / advanced testing in econometrics\") OR (\"advanced editing in econometrics / advanced editing in econometrics\"))))".
• Removing quotes may allow a broader search: (( advanced text in econometrics / advanced text in econometrics ) or ((( advanced testing in econometrics / advanced testing in econometrics ) OR ( advanced editing in econometrics / advanced editing in econometrics )))).
• Adding a wildcard symbol may retrieve word variants: (("advanced text in econometrics / advanced text in econometrics") or ((("advanced testing in econometrics / advanced testing in econometrics") OR ("advanced editing in econometrics / advanced editing in econometrics"))))*.