APA
National Building Agency, . (1981). Technical Note 9. Stone repair. Edinburgh: National Building Agency.
Chicago
National Building Agency, . 1981. Technical Note 9. Stone repair. Edinburgh: National Building Agency.
Harvard
National Building Agency, . (1981). Technical Note 9. Stone repair. Edinburgh: National Building Agency.
MLA
National Building Agency, . Technical Note 9. Stone repair. Edinburgh: National Building Agency. 1981.