To zoom, make sure your browser zoom is at the standard(100%). 

Then, click in the center of the page you are reading to zoom.

V1 and V2 viewers will have a fixed click in click out zoom.

V3 Publications have an adjustable zoom on the right hand side of the page. Wait until the texthas cleared and is readable.

If the page continues not to zoom, please ensure that your JavaScript isenabled within your browser.
If this does not work, try using different browser (E.g. Safari, Chrome,Firefox)