Here is a <blockquote> with a citation:
They went in single file, running like hounds on a strong scent, and an eager light was in their eyes. Nearly due west the broad swath of the marching Orcs tramped its ugly slot; the sweet grass of Rohan had been bruised and blackened as they passed.
Here's an example of nested quotations using the <q> tag:
John said, I saw Lucy at lunch, she says
Mary wants you
to get some ice cream on your way home.
I think I will get
some at Ben and Jerry’s, on Gloucester Road.
It should look like this:
John said, "I saw Lucy at lunch, she says 'Mary wants you to get some ice cream on your way home.' I think I will get some at Ben and Jerry’s, on Gloucester Road."