Ingenta proposes two tools in the forms of bookmarklets (simple tools that extend the surf and browse capabilities of your web browser) to augment google scholar that could be useful:

Google Scholar Highlighter: If you use Google Scholar, this bookmarklet will highlight the citations in your search results which have full text on IngentaConnect. Run your search and then click on the toolbar link to highlight the IngentaConnect results.

Search IngentaConnect via Google Scholar: Use Google Scholar to search IngentaConnect. Highlight words on any web page and click the link, or enter words into the pop-up box. Your search will be executed on Google but the results will be limited to those available on IngentaConnect.