Sova, Deborah Hinderer. : 233 tips and tricks for recruiting users as participants in usability studies / by Deborah Hinderer Sova and Jakob Nielsen. [O'Reilly electronic resource]
Sovereign Pictures (Firm) : Where angels fear to tread [(DVD) videorecording] / New Line Home Entertainment ; Sovereign Pictures in association with LWT and Derek Granger and Jeffrey Taylor for Stagescreen Productions presents a Charles Sturridge film ; produced by Derek Granger ; screenplay by Tim Sullivan, Derek Granger, Charles Sturridge ; directed by Charles Sturridge.