Scattered sources - reliable sources? On the documentation of those deported to the Mauthausen concentration camp who were not registered and died after liberation

Mauthhausen concentration camp was liberated in May 1945. Many of the liberated prisoners were so weak that they did not survive for long. Some were trampled to death, and the Kapos fell victim to their fellow prisoners' vengeance and were lynched. All these former inmates who died after liberation are still to be considered as victims of the SS's regime of terror, and one of the aims of this book is to determine the number and identities of those who died