It is always good practice to read and reference the original source of a work. If this is not possible you need to include the secondary source in your reference list, i.e the item you are using (whether it is a book, journal article or any other material) and acknowledge the original source by using the phrase (as cited in ...) in your in-text citation.

Original Source: MacGilchrist (not consulted)
Secondary Source: Brundrett & Rhodes (consulted)

In-text:

MacGilchrist argues that ....(as cited in Brundrett & Rhodes, 2011, p. 99)

Reference List:

Brundrett, M., & Rhodes, C. (2011). Leadership for quality and accountability in education. London: Routledge.