Single-stranded DNA prep reference?

[David Nunn]

  HELP, I saw an article recently that suggested that better yields of 
single-stranded template from phagemids could be obtained by preparing 
competent cells from a strain of E. coli preinfected with a helper phage 
(think it was M13KO7) and transforming them with the phagemid clone of 
choice. After slapping myself upside the head for forgetting where I saw 
the article (or xeroxing it at the time like I should have), can anybody 
out there tell me where they might have seen it. Appreciate it.