where can I find captivate 6 trial to download

I have upgrade captivate form 4 to 7, to my superise 7 couldn't see captivate 4 files as I were told I need captivate 5.5 or 6 to convert the file, so I went to find to my superise again I couldn't find one in Adobe web site, so please help where can I find one.

Thanks and regards

Lurther