Why do you want to select both “official” and “non-sanctioned” artifacts when you are trying to learn about an organizational culture?

What will be an ideal response?

Drawing on the idea that culture is both a top-down and bottom up phenomenon, you might get only the view of culture from organizational leaders in official publications. This may be how they want the culture to be, but not necessarily what it is from the grassroots perspective. You would want to further explore whether the view of culture of organizational leaders is broadly shared by employees at all levels of the organization.