A few more runtime updates.
diff --git a/runtime/syntax/bib.vim b/runtime/syntax/bib.vim
index f96553e..f2b99e9 100644
--- a/runtime/syntax/bib.vim
+++ b/runtime/syntax/bib.vim
@@ -2,7 +2,7 @@
" Language: BibTeX (bibliographic database format for (La)TeX)
" Maintainer: Bernd Feige <Bernd.Feige@gmx.net>
" Filenames: *.bib
-" Last Change: 2016 May 31
+" Last Change: 2016 Sep 12
" Thanks to those who pointed out problems with this file or supplied fixes!
@@ -71,7 +71,7 @@
" Clusters
" ========
-syn cluster bibVarContents contains=bibUnescapedSpecial,bibBrace,bibParen
+syn cluster bibVarContents contains=bibUnescapedSpecial,bibBrace,bibParen,bibMath
" This cluster is empty but things can be added externally:
"syn cluster bibCommentContents
@@ -81,6 +81,7 @@
syn match bibKey contained /\s*[^ \t}="]\+,/hs=s,he=e-1 nextgroup=bibField
syn match bibVariable contained /[^{}," \t=]/
syn region bibComment start=/./ end=/^\s*@/me=e-1 contains=@bibCommentContents nextgroup=bibEntry
+syn region bibMath contained start=/\$/ end=/\$/ skip=/\(\\\$\)/
syn region bibQuote contained start=/"/ end=/"/ skip=/\(\\"\)/ contains=@bibVarContents
syn region bibBrace contained start=/{/ end=/}/ skip=/\(\\[{}]\)/ contains=@bibVarContents
syn region bibParen contained start=/(/ end=/)/ skip=/\(\\[()]\)/ contains=@bibVarContents