contributors, "Ship" Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Ship&oldid=110777597 (accessed February 25, 2007). Wikipedia contributors
Wikipedia contributors، «Population density،» Wikipedia، The Free Encyclopedia، http://en.wikipedia.org/w/index.php?title=Population_density&oldid=197731677
contributors، «List of cities in Armenia،» Wikipedia، The Free Encyclopedia، http://en.wikipedia.org/w/index.php?title=List_of_cities_in_Armenia&oldid=206189462
objects," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=List_of_Messier_objects&oldid=268876608 (accessed February 9, 2009)
objects," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=List_of_Messier_objects&oldid=268876608 (accessed February 9, 2009)