Palmer, Christopher (2003). "Generation Starships and After: 'Never Anywhere To Go But In'?". Extrapolation. 44 (3): 321–322. doi:10.3828/extr.2003.44.3.06.
Suvin, Darko; Rossi, Umberto; Redondo, Juan C. Toledano; Trushell, John Michael; Levy, Mike (2002). "Goodbye and Hello: Differentiating Within the Later P.K. Dick". Extrapolation. 43 (4): 374. doi:10.3828/extr.2002.43.4.3.