diff --git a/src/app/app.routing.ts b/src/app/app.routing.ts
index 18dc71fc..51eaf8de 100644
--- a/src/app/app.routing.ts
+++ b/src/app/app.routing.ts
@@ -43,7 +43,7 @@ const appRoutes: Routes = [
         component: IntroductionComponent
     },
     {
-        path: 'leooIVA_IV_intro',
+        path: 'leoo4A_4_intro',
         component: LeceLeooComponent
     },
     {
diff --git a/src/app/biography/biography.component.html b/src/app/biography/biography.component.html
index 1f31d2c8..c01db253 100644
--- a/src/app/biography/biography.component.html
+++ b/src/app/biography/biography.component.html
@@ -326,10 +326,10 @@ <h2>Additional</h2>
                         </mat-form-field>
                     </p>
                     <p>
-                        <mat-card class="intro-card" appearance="outlined" routerLink="/leooIVA_IV_intro">
+                        <mat-card class="intro-card" appearance="outlined" routerLink="/leoo4A_4_intro">
                             <mat-card-content>
                                 <mat-card-title>Introduction</mat-card-title>
-                                Leonhardi Euleri Opera Omnia IVA/IV
+                                Leonhardi Euleri Opera Omnia 4A/4
                             </mat-card-content>
                         </mat-card>
                         <mat-card class="intro-card" appearance="outlined" routerLink="/lece_intro">
diff --git a/src/app/lece-leoo/lece-leoo.component.html b/src/app/lece-leoo/lece-leoo.component.html
index 45efd699..8981db17 100644
--- a/src/app/lece-leoo/lece-leoo.component.html
+++ b/src/app/lece-leoo/lece-leoo.component.html
@@ -13,8 +13,8 @@
 
         <div class="main-content" [ngSwitch]="url">
 
-            <ng-container *ngSwitchCase="'leooIVA_IV_intro'">
-                <h1>Leonhardi Euleri Opera Omnia IVA/IV</h1>
+            <ng-container *ngSwitchCase="'leoo4A_4_intro'">
+                <h1>Leonhardi Euleri Opera Omnia 4A/4</h1>
 
                 <div class="row">
                     <mat-card class="intro-card" appearance="outlined" routerLink="/introduction/leoo/goldbach_preface">