Area code 412 (English Wikipedia)

Analysis of information sources in references of the Wikipedia article "Area code 412" in English language version.

refsWebsite

Global rank English rank

6^th place

6^th place

1nationalnanpa.com

2,470^th place

1,321^st place

archive.org (Global: 6^th place; English: 6^th place)

Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone Magazine. 26 (4): 181. Retrieved 2022-04-23.

nationalnanpa.com (Global: 2,470^th place; English: 1,321^st place)

"Planning Letter PL-281: Rationing in NPAs 412, 724, and 878 (Pennsylvania)" (PDF). NANPA. 2001-05-14. Retrieved 2023-06-23.