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Pennsylvania This site contains files in PDF format. |
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Pennsylvania This site contains files in PDF format. |
| George S. Webster and Samuel Tobias
Wagner, "History of the Pennsylvania Avenue Subway, Philadelphia,
and Sewer Construction Connected Therewith," Transactions
of the American Society of Civil Engineers, Volume XLIV (December
1900), pp. 1-33 and plates I - IV. |
| Grant M. Olewiler, "Sewer Maintenance," Sewage Works Journal, Volume IX, No. 5 (September 1937), pp. 808-820. Frames version with JavaScript. PDF version (printer-friendly). |
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