[RefModel] Copyright © 1996 X/Open Company Limited. 1-85912-170-5. X/Open Company Ltd., U.K.. Distributed Transaction Processing: Reference Model, Version 3 .
[TXspec] Copyright © 1995 X/Open Company Limited. 1-85912-094-6. X/Open Company Ltd., U.K.. Distributed TP: The TX (Transaction Demarcation) Specification .
[XAspec] Copyright © 1991 X/Open Company Limited. 1-872630-24-3. X/Open Company Ltd., U.K.. Distributed TP: The XA Specification .
[XA+spec] Copyright © 1994 X/Open Company Limited. 1-85912-046-6. X/Open Company Ltd., U.K.. Distributed TP: The XA+ Specification Version 2 .