On logging in to the journal, you will arrive at the User Home page.

To see the submissions you need to review, click the Reviewer link, or click the "x" Active link. Both will take you to your active Submissions page. This page lists the submissions which you have been invited to review or are currently in the process of reviewing. The Submissions queue also notes what round the review is, as some reviews may have entered a second round of reviewing, following the Section Editor's decision that the submission must be "resubmitted for review." This page also provides access to past reviews which the Reviewer has completed for the journal.

Clicking on the linked title will take you to the review process.