2010AASHTO M 91-2010 Standard Specification for Sewer and Manhole Brick (Made from Clay or Shale)
2007AASHTO M 91-2007 Standard Specification for Sewer and Manhole Brick (Made from Clay or Shale)
0000 AASHTO M 91-2005
1995AASHTO M 91-1995 Standard Specification for Sewer and Manhole Brick (Made from Clay or Shale) HM-22; PART IA; ASTM Designation: C 32-93 (1999) R(2000)