v. 1. Coastal brick and stone forts / A. Konstam -- v. 2. Land and field fortifications / Ron Field https://siris-libraries.si.edu/ipac20/ipac.jsp?&profile=liball ...
https://siris-libraries.si.edu/ipac20/ipac.jsp?&profile=liball&source=~!silibraries&uri=full=3100001~!301047~!0#focus ...