The possible existence of rogues went back a long way, farther than 1900.

Some tours include information about the possible existence of ghosts within the prison.

Despite this, some pseudo-scientific organizations still try to present a case for its possible existence.

That depended on the possible existence of a further menace.

The possible existence of a third letter made it difficult to think of anything else.

The possible existence of this disorder was first described in 1993.

He, too, had never considered the possible existence of defensive circuits.

When the quasicrystals were first observed in 1982, their possible existence had already been predicted.

What you describe indicates the possible existence of a highly advanced technology.

Each step is thought to represent 100,000 life forms of a possible 8.4 million existences.