"'And so ad infinitum (The Life of the Insects) : An Entomological Review in Three Acts, a Prologue and an Epilogue " by Karel Capek, Josef Capek, (p. 60), 1936.
Mark Twain (2017). “Mark Twain, the Globetrotter: Complete Travel Books, Memoirs & Anecdotes (Illustrated Edition): A Tramp Abroad, The Innocents Abroad, Roughing It, Old Times on the Mississippi, Life on the Mississippi, Following the Equator & Some Rambling Notes of an Idle Excursion, With Author’s Biography”, p.1235, e-artnow