I think it's more just sloppy old translations and scribing if anything. Their translation of Capital is iirc an old one that's not used much for academic citations anymore for example. If you have something in print they have, it's possible you have a different edition or translation etc. that gives a different meaning to the text.
If you're just looking for Marx and Engels, the MEGA project has scans of everything they ever wrote, however it is in the original German/French/English depending on the document.
I think it's more just sloppy old translations and scribing if anything. Their translation of Capital is iirc an old one that's not used much for academic citations anymore for example. If you have something in print they have, it's possible you have a different edition or translation etc. that gives a different meaning to the text.
If you're just looking for Marx and Engels, the MEGA project has scans of everything they ever wrote, however it is in the original German/French/English depending on the document.
Okie, this is good to know. I get somewhat paranoid about this kind of stuff, don't want to be learning the wrong thing etc.