But by dusk we had not seen a single footprint, much less any sign of a trail.

"He never left a single footprint," the announcer says.

That afternoon they found a single footprint in one of these snow patches.

In the mud between the broken plants, he saw a single footprint that might have been Uhura's.

Aside from the dog tracks, we found a single footprint of what appeared to be a large, naked human foot.

It's a hugely sensitive environment where a single footprint can last for years.

And no matter how you look at it, one single footprint from a different pair of shoes adds up to what?

There isn't a single footprint left up here, naked or otherwise!

Bleomycin produces a single large footprint which covers the entire insert.

No single footprint had as yet marked this pure layer.