Standards are published and managed by TIA.  A full tabulation of published standards is maintained by TIA at their website: http://www.tiaonline.org/standards/ .

The primary activity for developing the many Project 25 technology standards are governed under the TIA Engineering Committee TR8, Mobile and Personal Private Radio Standards.  Project 25 standards development activity is recorded and reported on at the same TIA website under the TR8 Engineering Committee listings.  The multiple subcommittees and working group reports are all accessible at the TIA website referenced.

Published Standards Are Available for Purchase:
Standards can be purchased through IHS International/Global Services.  This is the publication firm appointed by TIA as the primary distributor of standards and related publications.  While TIA/TR8 and their associated technical groups continue standards development, IHS is responsible for publication, sale and distribution.

Contact Information is:
IHS International Inc.
http://www.ihs.com
1-800-854-7179 (U.S. and Canada)
1-303-397-7956 (Outside U.S. and Canada)

FREE DOWNLOADS TO GOVERNMENT ENTITIES:
Free Downloads are available only to qualified government entities.  The qualified government requestor must contact TIA, and initiate a request for access to a password secured FTP website managed by TIA.

Recently a new page is available at tiaonline.org which provides an easy way for government agencies to request a free copy of the TIA P25 Standards.

Here is the link direct to TIA:  http://www.tiaonline.org/all-standards/p25-downloads-application