STALLCUP, J. G. (1989). Illustrated changes: Of the 1990 NEC. American Technical Pub.
Chicago-čujuhus (17. p.)STALLCUP, James G. Illustrated Changes: Of the 1990 NEC. Homewood: American Technical Pub, 1989.
MLA-čujuhus (9. p.)STALLCUP, James G. Illustrated Changes: Of the 1990 NEC. American Technical Pub, 1989.
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