Barbeau, Joseph E.
Custom book program of northeastern University , 1985
Buku Teks
Washington U.S. Department of Health, Education, and Welfare 1955
Buku Teks
Spanbauer, Stanley J.
ASQC Quality Press, 1993
Buku Teks
Frederick, Robert W.
USA Appleton 1947
Buku Teks
Tokyo, Nanzan University, 2003
Majalah, Jurnal, Buletin