TY  - BOOK
AU  - Frye, David
TI  - Walls: a history of civilization
SN  - 9780571348428
PY  - 2018///
CY  - UK
PB  - Faber& faber
KW  - Civilization
KW  - Military architecture
KW  - Military field engineering
KW  - Fortification
KW  - Earthworks (Archaeology)
ER  -