20th century Timeline of Philadelphia

^ new york times 2013: 4 square blocks
^ federal writers project 1937.
^ city clubs in america, chicago: city club of chicago, 1922 
^ history . economy league of greater philadelphia. retrieved november 21, 2013. 
^ cite error: named reference brenner2009 invoked never defined (see page).
^ britannica 1910.
^ movie theaters in philadelphia, pa . cinematreasures.org. los angeles: cinema treasures llc. retrieved october 2, 2013. 
^ nina mjagkij (1994). light in darkness: african americans , ymca, 1852-1946. university press of kentucky. isbn 0-8131-2801-3. 
^ goodale, gloria (june 17, 2011). superhero summer: behind green lantern , rest, american story . christian science monitor: 2. archived original on june 23, 2011. 
^ walter s. hayward; percival white (1922), chain stores: management , operation, new york: mcgraw-hill 
^ cite error: named reference impacprints invoked never defined (see page).
^ colored dunbar theatre . crisis. national association advancement of colored people. 19 (6). april 1920. 
^ cite error: named reference statab2003 invoked never defined (see page).
^ cite error: named reference loc invoked never defined (see page).
^ evensen 1993.
^ historic theatre inventory . maryland, usa: league of historic american theatres. retrieved october 4, 2013. 
^ nina mjagkij, ed. (2001), organizing black america: encyclopedia of african american associations, garland, isbn 9780815323099 
^ cite error: named reference hsp-african invoked never defined (see page).
^ philadelphia, pennsylvania . global nonviolent action database. cases: united states. pennsylvania: swarthmore college. retrieved october 10, 2013. 
^ richard kurin (2013). smithsonian s history of america in 101 objects. penguin. isbn 978-1-101-63877-4. 
^ cite error: named reference uartsname invoked never defined (see page).
^ philadelphia city archives . city of philadelphia. retrieved may 30, 2015. 
^ miller 1983.
^ pennsylvania , official congressional directory, 1959 
^ robert l. harris jr.; rosalyn terborg-penn (2013). chronology . columbia guide african american history since 1939. columbia university press. isbn 978-0-231-51087-5. 
^ timeline: local events national significance . civil rights in northern city: philadelphia. temple university. retrieved october 15, 2013. 
^ sister cities . citizen diplomacy international - philadelphia. retrieved december 30, 2014. 
^ 50 years of regional planning (timeline) . philadelphia: delaware valley regional planning commission. retrieved september 12, 2016. 
^ shca . philadelphia: society hill civic association. retrieved october 2, 2013. 
^ urban archives . temple university, libraries. retrieved may 30, 2015. 
^ robin d. g. kelley , earl lewis, ed. (2005). chronology . make our world anew: history of african americans. oxford university press. isbn 978-0-19-983893-6. 
^ mariposa food co-op . philadelphia: mariposa food co-op. retrieved november 5, 2013. 
^ ncga co-ops: pennsylvania . iowa: national cooperative grocers association. retrieved november 5, 2013. 
^ anastasia, george (1991). blood , honor: inside scarfo mob – mafia s violent family. new york: william morrow , company inc. pp. 86–88. isbn 0-688-09260-8. 
^ anastasia (1991), pp. 91-92
^ pluralism project. hinduism in america . america s many religions: timelines. harvard university. retrieved october 4, 2013. 
^ cite error: named reference newmuseum invoked never defined (see page).
^ population of 100 largest cities , other urban places in united states: 1790 1990, census bureau, 1998 
^ michael barone; chuck mccutcheon (2011). almanac of american politics 2012. washington, d.c.: national journal group. isbn 978-0-226-03807-0. 
^ phila.gov: official philadelphia website . archived original on december 1996 – via internet archive, wayback machine.