Analysis of information sources in references of the Wikipedia article "Bell 206" in English language version.
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: CS1 maint: archived copy as title (link) George A. Spangenberg Oral History. spangenberg.org. Judith Spangenberg-Currier, ed. pp. 187–190. Accessed on April 29, 2008{{cite web}}
: CS1 maint: archived copy as title (link) George A. Spangenberg Oral History. spangenberg.org. Judith Spangenberg-Currier, ed. pp. 187–190. Accessed on April 29, 2008