I know the construction pros on this site can tell me where I can find this type of plywood. It is used a lot in the construction trade where strength is a must such as concrete forms and other areas like this. If I could find a few used sheets that were in good shape I’d love that but if I need to buy a few new sheets I’m good with that also. I need it to be 5/8 inch thick (4x8 sheets). There has to be a store that sells this type plywood. I’m making some specialized bee equipment with it. All of the big beekeepers use this stuff. It last a long time plus it’s tough as all get out. Thanks for the help.