Here is a good link to important publications in PDF format. I download them to my Itouch to use with a PDF reader having them available virtually wherever I am.
http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0001 (http://msi.nga.mil/NGAPortal/MSI.portal?_nfpb=true&_pageLabel=msi_portal_page_62&pubCode=0001)
Grog-worthy!
Thanks!