using System;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		string[] inp = new string[] {
			"Some words",
			"Some words and some other words",
			"Some words, more words and some other words",
			"Some words, more words, and some other words" 
		};
		foreach (string s in inp) {
			string[] phrases = (Regex.Split(s, @"(?:,\s*|\s+)and\s+|,\s*"));
			Console.WriteLine(string.Join("\n", phrases));
		}
	}
}

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