sort grouped citations in bibliography by year

Hi everyone,

I am working on a manuscript for a journal that wants the citations and bibliography in the following form:

  1. citation in text -> grouped and sorted by number

  2. bibliography

references grouped ie. [1] a)…; b)…; c) …

AND sorted by year

My following problem is that the references in the bibliography are sorted in alphabetical order (name first author).

For this the settings are:

edit style  -> citations -> sort order -> same as bibliography

bibliography  -> sort order -> order of apperance

What I tried:

  1. change the sort order under bibliography to -> year+author

=> results in loss of grouping of the references, meaning every reference gets its own number

  1. change the sort oder under citations -> sort order -> year+author

=> now I get the references grouped and in the bibliography sorted by year

BUT now the references in the text are not [1a,5,7] but for instance [7, 1a, 5]

Anyone an idea?