You wrote
One solution is possible: to copy the .bst file I use and patch it ... which also means potential compatibility problems. Is there more direct solution?
I can't see which "potential compatibility problems" you might encounter if you modify a copy of an existing bst (bibliography style) file properly.
I take it that you're mostly interested in the ugost2008n
bibliography style and that the main change you want to implement is to modify the truncation criterion for how many authors are shown in the formatted bibliographic entries. The default criterion is 4, meaning that if an entry has 4 or fewer authors (or editors), all authors are shown, whereas if the entry has 5 or more authors (or editors), only the first 3 names plus "et al" get displayed.
To change the cut-off criterion to, say, 5, I suggest you proceed as follows:
Find the file ugost2008n.bst
in your TeX distribution and make a copy of this file. Name the copy ugost2008n5.bst
.
Find the function format.names
, which starts on line 767 of my copy of the file. (I have version 1.2d of the file, dated 2016/02/18.) The first few lines of this function should look as follows:
FUNCTION {format.names}
{
's :=
#1 'nameptr :=
s num.names$ 'numnames :=
numnames 'namesleft :=
{ namesleft #0 > }
{ s nameptr
"{vv~}{ll}{~jj}{~ff}" format.name$ 't :=
nameptr #1 >
{ nameptr #4 =
numnames #4 > and
{ "others" 't :=
#1 'namesleft := }
'skip$
if$
To change the truncation number from 4 to 5, simply change the two instances of #4
to #5
.
Save the file ugost2008n5.bst
either in the directory where your main tex file is located or in a directory that's searched by BibTeX. If you choose the latter method, be sure to update the filename database of your TeX distribution suitably.
Start using the newly-modified bibliography style by changing the instruction
\bibliographystyle{ugost2008n}
to
\bibliographystyle{ugost2008n5}
Be sure to rerun LaTeX, BibTeX, and LaTeX twice more to fully propagate all changes.
Happy BibTeXing!