using System;
using System.IO;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		var line = "@article{Gettys90,\n   author = {Jim Gettys and Phil Karlton and Scott McGregor},\n   abstract = {A technical overview of the X11 functionality. This is an update of the X10 TOG paper by Scheifler & Gettys.},\n   journal = {Software Practice and Experience},\n   volume = {20},\n   number = {S2},\n   title = {The {X} Window System, Version 11},\n   year = {1990}\n\n},\n\n\n@article{Gettys90,\n   author = {Jim Gettys and Phil Karlton and Scott McGregor},\n   abstract = {A technical overview of the X11 functionality. This is an update of the X10 TOG paper by Scheifler & Gettys.},\n   journal = {Software Practice and Experience},\n   volume = {20},\n   number = {S2},\n   title = {The {X} Window System, Version 11},\n   year = {1990}\n},\n@article{Gettys90,\n   author = {Jim Gettys and Phil Karlton and Scott McGregor},\n   abstract = {A technical overview of the X11 functionality. This is an update of the X10 TOG paper by Scheifler & Gettys.},\n\n  journal = {Software Practice and Experience},\n\n  volume = {20},\n   number = {S2},\n   title = {The {X} Window System, Version 11},\n   year = {1990}\n}";
        var kvp = @"(?<kvp>\W*([a-zA-Z]+) = {(.+?)},)";
        var pattern = string.Format("(?<entry>@(\\w+)\\{{(\\w+),{0}{0}*(\\W*([a-zA-Z]+) = \\{{(.+?)}})\\W*}},?\\s*)+", kvp);
        // No need to recurse (?<entry>) because we can just use `+` quantifier
        var matches = Regex.Matches(line, pattern);
            foreach (Match m in matches)
               Console.WriteLine(m.Groups["kvp"].Value);
        
	}
}