Memorial Hall Library

Iron and steel bridges -- Pennsylvania -- Philadelphia -- Design and construction -- History

Type

http://bibfra.me/vocab/lite/Concept

Label

Iron and steel bridges -- Pennsylvania -- Philadelphia -- Design and construction -- History

Name

Iron and steel bridges

Focus

Iron and steel bridges

Sub focus

Actions

Incoming Resources

Subject of
1
- Tom Paine's iron bridge, building a United States, Edward G. Gray

Outgoing Resources

Focus
1
- Iron and steel bridges
Sub focus
4