USA Softball of Massachusetts (usasoftballma.com)
USA Softball / NCAA / NFHS Rule Differences (teamusa.org)
Umpire Manual (teamusa.org)
​RegisterUSASoftball.com - Account-Login
​Official Gear (teamusa.org)   
USA Softball Northeast Region Tournaments (asanewengland.com)
USA-Massachusetts 2021 Registration Guide Updated 2020-12-10.pdf