Corpora: references

[Alejandro Curado Fuentes]

Dear All,
I am interested in getting the full reference for two papers: One by
Michael Lewis (1997), in which he declared that Corpus Linguistics is not
a branch but a way into Linguistics (IN case I am misinformed about the
author and date, please let me know).
The second source is, I believe, David Willis's Ph D Thesis on lexical
collocation (1998?).
Please forgive me for my uncertainties, but these are things one reads,
misplaces them, and never finds them again.
Thanks in advance
Best wishes
Alejandro