Core Literature

There are a number of important books in the "Gurdjieff Literature"
and all ranging from the sublime to nullified.
However, those on the level of sublime would clearly include
Beelzebub's Tales to His Grandson and Gurjieff's two other books that followed:
Meetings with Remarkable Men and
Life Is Real Only Then, When "I Am."

Gurdjieff however,  put special importance on "Beelzebub."
It is a book of immense depth and for many readers, a daunting undertaking.
But "The Tales," as it is also commonly referred, 
stands in a category all it's own.

Considering important books that
shed additional light on Gurdjieff's teaching, these would include 
P.D. Ouspenky's In Search on the Miraculous.
In some regards, this book is like a diary of Ouspenky's years with
Gurdieff mostly from late 1915 to early 1918. 
Another important title would be Views from the Real World.
It is a book of recollected talks (as remembered by students)
given by Gurdjieff, mostly in the early to mid 1920's.
These above mentioned books, are generally considered the "core" literature.

Books high on the level of biographical accounts would be
Our Life with Mr. Gurdjieff (Olga and Thomas De Hartmann),
Journey With a Mystic (Fritz Peters), and Idiots in Paris (J.G. and Elizabeth Bennett).

Additional books of value that have immerged in the last few years are:
Exchanges Within (John Pentland),
Heart Without Measure (Ravi Ravindra),
Opening (William Segal) and A Taste for Things That Are True (Henri Tracol).

Beelzebub's Tales to His Grandson - G.I. Gurdjieff, Penguin/Arkana 1999

Meetings with Remarkable Men - G.I. Gurdjieff, Penguin/Arkana 2002

Life is Real Only Then, When "I Am" - G.I. Gurdjieff, Penguin/Arkana 1991

Views From the Real World - G.I. Gurdjieff, Penguin/Compass 1984

In Search of the Miraculous - P.D. Ouspensky, Harvest Books (Harcourt) 2001

Our Life with Mr. Gurdjieff - Olga and Thomas De Hartmann, Penguin/Arkana 1992

My Journey With a Mystic - Fritz Peters, Tale Weaver 1988

Idiots in Paris - J.G. and Elizabeth Bennett, Bennett Books 1991

Exchanges Within - John Pentland, Continuum Books 1997

Heart Without Measure - Ravi Ravindra, Shaila Press !999

Openings - William Segal, Continuum Books 1998

A Taste for Things That Are True - Henri Tracol, Element Books 1994