[R] Reference for dataset colon (package survival)

[Terry Therneau]

It has obviously been a very long time since I wrote that manual page.
I've now updated it with the following which will show up in the next
release.

\note{The study is described in Laurie et al.  A version of the data
  set with less follow-up time is used in the paper by Lin.}
   
\references{
  JA Laurie, CG Moertel, TR Fleming, HS Wieand, JE Leigh, J Rubin,
  GW McCormack, JB Gerstner, JE Krook and J Malliard.  Surgical
  adjuvant therapy of large-bowel carcinoma: An evaluation of
  levamisole and the combination of levamisole and fluorouracil:
  The North Central Cancer Treatment Group and the Mayo Clinic.
  J Clinical Oncology, 7:1447-1456, 1989.

  DY Lin.  Cox regression analysis of multivariate failure time data:
  the marginal approach.  Statistics in Medicine, 13:2233-2247, 1994.
  }

Thanks for the prompt.

Terry Therneau

--------- begin included message -----
Dear R team, dear Prof. Therneau,

library(survival)
data(colon)
?colon

gives me only a very rudimentary source (only a name). Is there a 
possibility to get a reference to the clinical trial these data
are taken from?