Puerto Rican Winter League: José A. Crescioni Benítez, El Béisbol Profesional Boricua (San Juan, PR: Aurora Comunicación Integral, Inc., 1997). This valuable history is not a full encyclopedia; Sr. Crescioni also furnished many numbers from his private database.

Minor Leagues: Midre Cummings 1999, Calvin Pickering 1999-2000 from Baseball America.
Numbers not available on baseball cards were provided by Pat Doyle, who operates a minor league player research service.
E-mail specific requests to Pat at bbdata@aol.com or visit his Old-Time Data web page.

Mexican League: Enciclopedia del Béisbol Mexicano, Pedro Treto Cisneros, Editor (Mexico City, Mexico: Revistas Deportivas, S.A. de C.V. 1998).

Negro Leagues: Alfonso Gerard's available numbers courtesy of Dick Clark. Unfortunately, black baseball's records are far from complete -- and after Jackie Robinson's major-league debut, the African-American newspapers devoted less effort to scorekeeping.

Dominican League: There is no encyclopedia of Dominican baseball or even a book as comprehensive as Sr. Crescioni's. It appears from local newspapers that many historical numbers are available, but we are still trying to obtain them.