Dyfyniad APA

Hartwell, F. P. (2021). McGraw-Hill's national electrical code 2020 handbook (Thirtieth edition.). McGraw Hill.

Dyfyniad Arddull Chicago

Hartwell, Frederic P. McGraw-Hill's National Electrical Code 2020 Handbook. Thirtieth edition. New York: McGraw Hill, 2021.

Dyfyniad MLA

Hartwell, Frederic P. McGraw-Hill's National Electrical Code 2020 Handbook. Thirtieth edition. McGraw Hill, 2021.

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