Public domain. Cover image from Project Gutenberg ebook #72190. The silent invaders auctore Robert Silverberg Detrahe .m4b · 72 MB Quomodo audiendum → · Problema cum hac recitatione? Animadversionem mitte → Recitator Arthur — English RP Narrator (en-GB) Diuturnitas 1 hr 13 min Lingua English Additum November 5, 2026 Liber electronicus originalis Project Gutenberg Licentia Public domain FictionScience Fiction