>>349 補足
AMSの本の目次に、下記のように、リンクがあって、”The book is suitable for graduate students and researchers interested in the theory of finite groups. ”だと
で、google book状態で、見るだけなら、かなり内容が読める（＾＾
（他の本もそうかも）
http://bookstore.ams.org/surv-111
The Classification of Quasithin Groups: I. Structure of Strongly Quasithin " mathcal-groups
(抜粋)

Around 1980, G. Mason announced the classification of a certain subclass of an important class of finite simple groups known as "quasithin groups". The classification of the finite simple groups depends upon a proof that there are no unexpected groups in this subclass. Unfortunately Mason neither completed nor published his work.
An important corollary of the Main Theorem provides a bridge to the program of Gorenstein, Lyons, and Solomon (Volume 40 in the AMS series, Mathematical Surveys and Monographs) which seeks to give a new, simplified proof of the classification of the finite simple groups.
The book is suitable for graduate students and researchers interested in the theory of finite groups.

Introduction to Volume I 18
http://bookstore.ams.org/surv-111/18
Introduction to Volume I
The treatment of the " quasithin groups of even characteristic" is one of the
major steps in the Classifcation of the Finite Simple Groups. (for short, the
Classifcation). As a part of the original Classifcation program, Geoff Mason
announced a classifcation of a subclass of the quasithin groups in about 1980, but he
never published his work, and the preprint he distributed [Mas] is incomplete in
various ways. In two lengthy volumes, we now treat the quasithin groups of even
characteristic; in particular, we close that gap in the proof of the Classifcation.

[Mas] G. Mason, The classifcation of finite quasithin groups, typescript, U. California Santa
Cruz, about 1981 about 800 pages,.