Biology was one of his main interests, and there is extensive biological material in his extant writings.

There are no extant writings from within 2 generations of his "existence" (average life expectancy then was 28).

This can be confirmed from the extant writings of Origen.

There are also several extant original writings by Alexander.

Indeed all the extant writings by which he has earned his place as a poet and translator belong to this period.

These two letters are thought to be the oldest extant writing by a Roman woman found in Britain, or perhaps anywhere.

This approach thus uses what an author "should have said" rather than what is available in the author's extant writings.

Little beyond this essay is known of Gaunilo; no other extant writings bear his name.

His extant writings are proof that Alvarus did not exaggerate.

All known and extant writings attributed to Robert Henryson are listed here.