During the first nine decades of last century, no fewer than 20 governments reached the dubious milestone of 1,000,000 murdered civilians.

One of those governments was Nazi, and six of them were Communist. The others...?

Full text of Professor Rummel's book "Death By Government":

https://cloudflare-ipfs.com/ipfs/bafykbzacecowyfyu2gxz4wwjdtthfv5cbsk5ar24o4k63er2dufcbrlngwet4?filename=R.%20J.%20Rummel%20-%20Death%20by%20Government-Transaction%20Publishers%20%281997%29.pdf