diff --git a/lib/Graph.js b/lib/Graph.js
index 3a4ee04..c4edfb8 100644
--- a/lib/Graph.js
+++ b/lib/Graph.js
@@ -141,11 +141,21 @@ Graph.prototype.toArray = function toArray() {
 	var triples = [];
 	var data = this.indexPSO;
 	if(!data) return [];
-	(function go(data, c){
-		if(c) Object.keys(data).forEach(function(t){go(data[t], c-1);});
-		else triples.push(data);
-	})(data, 3);
-	return triples;
+	// Use a stack to avoid recursion
+    var stack = [{ node: data, depth: 3 }]; 
+    while (stack.length > 0) {
+        var current = stack.pop();
+        var currentNode = current.node;
+        var currentDepth = current.depth;
+        if (currentDepth > 0) {
+            Object.keys(currentNode).forEach(function (key) {
+                stack.push({ node: currentNode[key], depth: currentDepth - 1 });
+            });
+        } else {
+            triples.push(currentNode);
+        }
+    }
+	return triples.reverse();
 };
 Graph.prototype.filter = function filter(cb){
 	var result = new Graph;