diff --git a/index.html b/index.html
index 02c8771..4708811 100644
--- a/index.html
+++ b/index.html
@@ -54,16 +54,19 @@
                 </p>
                 <div class="grid md:grid-cols-3 gap-6 max-w-4xl mx-auto text-center">
                     <div class="bg-white/10 backdrop-blur-sm rounded-lg p-4">
-                        <div class="text-3xl font-bold">$1.75T</div>
+                        <div class="text-3xl font-bold">$1.81T</div>
                         <div class="text-sm opacity-90">Total U.S. Student Debt</div>
+                        <div class="text-xs opacity-75 mt-1">Education Data Initiative, 2025</div>
                     </div>
                     <div class="bg-white/10 backdrop-blur-sm rounded-lg p-4">
-                        <div class="text-3xl font-bold">45M</div>
+                        <div class="text-3xl font-bold">42.5M</div>
                         <div class="text-sm opacity-90">Americans with Student Loans</div>
+                        <div class="text-xs opacity-75 mt-1">Education Data Initiative, 2025</div>
                     </div>
                     <div class="bg-white/10 backdrop-blur-sm rounded-lg p-4">
-                        <div class="text-3xl font-bold">$37K</div>
-                        <div class="text-sm opacity-90">Average Debt per Borrower</div>
+                        <div class="text-3xl font-bold">$39K</div>
+                        <div class="text-sm opacity-90">Average Federal Debt per Borrower</div>
+                        <div class="text-xs opacity-75 mt-1">Education Data Initiative, 2025</div>
                     </div>
                 </div>
             </div>
@@ -446,11 +449,11 @@
                                         <ul class="space-y-2 text-sm text-gray-600">
                                             <li class="flex items-start">
                                                 <span class="text-green-500 mr-2">•</span>
-                                                <span><strong>Investment Returns:</strong> 7% average annual return (historical S&P 500 average)</span>
+                                                <span><strong>Investment Returns:</strong> 7% average annual return <em>(S&P 500 long-term average: 9.96% nominal, ~7% real after inflation - Investopedia, 2025)</em></span>
                                             </li>
                                             <li class="flex items-start">
                                                 <span class="text-green-500 mr-2">•</span>
-                                                <span><strong>Loan Interest Rate:</strong> 5% annual rate (federal student loan average)</span>
+                                                <span><strong>Loan Interest Rate:</strong> 5% annual rate <em>(representative federal student loan rate)</em></span>
                                             </li>
                                             <li class="flex items-start">
                                                 <span class="text-green-500 mr-2">•</span>
@@ -464,11 +467,16 @@
                                     </div>
                                 </div>
                                 
-                                <div class="mt-4 p-4 bg-amber-50 rounded-lg">
-                                    <p class="text-sm text-amber-800">
-                                        <strong>Note:</strong> This calculator provides estimates for educational purposes. Actual results will vary based on your specific loan terms, employer plan details, investment performance, and contribution consistency. Consult with a financial advisor for personalized advice.
-                                    </p>
-                                </div>
+                <div class="mt-4 p-4 bg-amber-50 rounded-lg">
+                    <p class="text-sm text-amber-800">
+                        <strong>Note:</strong> This calculator provides estimates for educational purposes. Actual results will vary based on your specific loan terms, employer plan details, investment performance, and contribution consistency. Consult with a financial advisor for personalized advice.
+                    </p>
+                    <div class="mt-3 pt-3 border-t border-amber-200">
+                        <p class="text-xs text-amber-700">
+                            <strong>Data Sources:</strong> Student loan statistics from Education Data Initiative (2025). Investment return assumptions based on S&P 500 historical performance data from Investopedia (2025). Federal Reserve household debt data from NY Fed Center for Microeconomic Data.
+                        </p>
+                    </div>
+                </div>
                             </div>
                         </div>
                     </div>
@@ -802,11 +810,27 @@ Best regards,
                             </a>
                         </li>
                         <li>
-                            <a href="https://www.fidelityworkplace.com/s/studentdebt-retirement"
+                            <a href="https://educationdata.org/student-loan-debt-statistics"
                                target="_blank" 
                                rel="noopener noreferrer"
                                class="hover:text-white transition-colors">
-                                Fidelity Student Debt Solutions
+                                Education Data Initiative - Student Loan Statistics
+                            </a>
+                        </li>
+                        <li>
+                            <a href="https://www.investopedia.com/ask/answers/042415/what-average-annual-return-sp-500.asp"
+                               target="_blank" 
+                               rel="noopener noreferrer"
+                               class="hover:text-white transition-colors">
+                                Investopedia - S&P 500 Historical Returns
+                            </a>
+                        </li>
+                        <li>
+                            <a href="https://www.newyorkfed.org/microeconomics/hhdc/background.html"
+                               target="_blank" 
+                               rel="noopener noreferrer"
+                               class="hover:text-white transition-colors">
+                                Federal Reserve Bank of NY - Household Debt Data
                             </a>
                         </li>
                     </ul>