diff --git a/spec/models/paper_spec.rb b/spec/models/paper_spec.rb
index 760da66..7c19298 100644
--- a/spec/models/paper_spec.rb
+++ b/spec/models/paper_spec.rb
@@ -3,5 +3,50 @@ require 'rails_helper'
 RSpec.describe Paper do
   context "Validations" do
     it { should validate_presence_of(:name) }
+    it { should validate_length_of(:name).is_at_most(1000) } 
+    
+    it { should validate_presence_of(:url) }
+    it { should validate_length_of(:url).is_at_most(1000) }
+    
+    context "URL uniqueness" do
+      subject { FactoryGirl.build(:paper) }
+      it { should validate_uniqueness_of(:url) }
+    end
+    
+    it "validate url format sane" do
+      expected_error = "ist keine gültige URL"
+      paper = FactoryGirl.build(:paper, url: "wtf")
+      expect(paper).not_to be_valid, "Expected paper to not be valid with invalid URL"
+      expect(paper.errors[:url]).not_to be_empty
+      expect(paper.errors[:url]).to include(expected_error), "Expected #{paper.errors[:url]} to include \"#{expected_error}\""
+    end
+
+    it { should validate_presence_of(:reference) }
+    it { should validate_length_of(:reference).is_at_most(100) }
+
+    it { should validate_presence_of(:body) }
+    it { should validate_length_of(:body).is_at_most(100) }
+
+    it { should validate_presence_of(:content) }
+    it { should validate_length_of(:content).is_at_most(100_000) }
+
+    it { should validate_presence_of(:originator) }
+    it { should validate_length_of(:originator).is_at_most(300) }
+
+    it { should validate_presence_of(:paper_type) }
+    it { should validate_length_of(:paper_type).is_at_most(50) }
+
+    context "published_at" do
+      it { should validate_presence_of(:published_at) }
+      it "validate date is parseable" do
+        expected_error = "ist kein gültiges Datum"
+        paper = FactoryGirl.build(:paper, published_at: "fubar")
+        expect(paper).not_to be_valid
+        expect(paper.errors[:published_at]).not_to be_empty
+        expect(paper.errors[:published_at]).to include(expected_error), "Expected #{paper.errors[:published_at]} to include \"#{expected_error}\""
+      end
+    end
+
+    it { should validate_length_of(:resolution).is_at_most(30_000) }
   end
 end