From Quality Software Management: Vol 2. First Order Measurement
Culture makes its presence known through patterns that persist over time.

One of the most sensitive measures of the cultural pattern of any organization is how quickly it finds and removes problems.

From The Toyota Way
Building a culture takes years of applying a consistent approach with consistent principles.

From XP and Culture Change
A process change will always involve a cultural change.

Because culture embodies perception and action together, changing culture is difficult and prone to backsliding.

From Quality Software Management: Vol 3. Congruent Action
Culture makes language, then language makes culture.

From Beating the System
Culture is what we do when we do not consciously decide what to do.

From Freedom from Command and Control
Consultants who see culture change as something distinct from the work and, as a corollary, something that can be the subject of an intervention, miss the point. When you change the way work is designed and managed, and make those who do the work the central part of the intervention, the culture changes dramatically as a consequence.

From Leverage points
One aspect of almost every culture is the belief in the utter superiority of that culture.

From John Seddon
Culture change is free [because] it's a product of the system.

From Notes on the Synthesis of Form
Culture is changing faster than it has ever changed before...what once took many generations of gradual development is now attempted by a single individual.

From Slack
Successful change can only come about in the context of a clear understanding of what may never change, what the organization stands for... the organization's culture... If nothing is declared unchangeable, then the organization will resist all change. When there is no defining vision, the only way the organization can define itself is its stasis.

From The Hidden Dimension
As Freud and his followers observed, our own culture tends to stress that which can be controlled and to deny that which cannot.

From The Silent Language
Culture hides much more than it reveals, and strangely enough what it hides, it hides most effectively from its own participants.

An often noted characteristic of culture change is that an idea or a practice will hold on very persistently, apparently resisting all efforts to move it, and then, suddenly, without notice, it will collapse.