Specification :

ISO/IEC 13818-7

Part 7: Advanced Audio Coding (AAC)

the lastest version is 2006

but we could not find the free one on internet,but only find another version :

Third edition

2004-10-15

the full name is :

Information technology — Generic
coding of moving pictures and
associated audio information —
Part 7:
Advanced Audio Coding (AAC)

its download address:

http://jongyeob.com/moniwiki/pds/upload/13818-7.pdf

also ,above page ,you can download other specification :

http://jongyeob.com/moniwiki/pds/upload/14496-3.pdf

http://jongyeob.com/moniwiki/pds/upload/14496-10.pdf

http://jongyeob.com/moniwiki/pds/upload/CM_product.pdf

that is :

13818-7.pdf             27-Jan-2005 15:33 1.2M
14496-3.pdf             27-Jan-2005 15:33   52M
14496-10.pdf            27-Jan-2005 15:33 1.9M
CM_product.pdf          27-Jan-2005 14:51   13M

you can see many other specification lists of ISO/IEC in this page:

http://www.itscj.ipsj.or.jp/sc29/29w42911.htm