Those 4 volumes do indeed cover all that Heim published in his lifetime warts and all i e volume 1 is still not totally error free though better than before And yes it is the famous 2000 page write up Note though that Heim left behind lots of notes that were never published Haeuser has thes and is sifting through them so may eventually add to the body of work In principle one could glean a quite thorough understanding of Heim Theory by reading the already existing 4 volumes If you have the money to spend on these then you could do worse than getting the set Resch also offers some volumes on the late John Paul II s list of saints they are probably more popular at the moment However there is a caveat physicists who have gone through them took on average over 1 year of intense study before they came to grips with the concepts there If you have the time to invest then by all means try that Alternatively or in addition to that you could also follow what appears on apparently in May Droescher will post a rigourous derivation of the eigen value equations that are the basis of the mass formula And on that web site they try to keep to normal mathematical notation