Mueller-Lutz, H.L.
Institut fuer Versicherungwissenschaft der Ludwig-Maximilians-Universitaet Muenchen, 1994
Buku Referensi
Brown, Robert H.
Witherby, 1975
Buku Teks
R & R Newkirk/Longman, 1985
Buku Referensi
Ingrisano, John R.
Chicago, Dearborn Financial Publishing, 1990
Buku Referensi
Bruce D. Mudget [and others]
Alexander Hamilton Institute, 1962
Buku Teks