New York City record and building trades directory (1892)
New York City Record Pub. Co · Park Row, N.Y. : New York City Record Pub. Co. · leaf 16
I Under PatentsfSI 1876,1878,1879,1882,1883, 1889,1891. … Sole Proprietor and only Blckelhoupt Manufacturing Skylights, Etc.,and C. Bickelhoupfs Vacuum Skylights of I 89 I.
Building · Building laws
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