The Amateur Softball Association of America. (1989). The Amateur Softball Association of America, official 1989 guide and rule book. Amateur Softball Association of America.
Citazione stile Chigago Style (17a edizione)The Amateur Softball Association of America. The Amateur Softball Association of America, Official 1989 Guide and Rule Book. Oklahoma City: Amateur Softball Association of America, 1989.
Citatione MLA (9a ed.)The Amateur Softball Association of America. The Amateur Softball Association of America, Official 1989 Guide and Rule Book. Amateur Softball Association of America, 1989.
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