diff --git a/lines/doi.py b/lines/doi.py
new file mode 100644
index 0000000..7aca4bd
--- /dev/null
+++ b/lines/doi.py
@@ -0,0 +1,35 @@
+def doi():
+    """
+    encapsulate author program in a
+    function
+    """
+    # imports
+
+    import nltk
+    import re
+
+    # file
+
+    f_name="BibTex.bib"
+
+    def opener(f_name):
+        file = open(f_name, 'r', encoding="utf8")
+        return file
+
+    file=opener(f_name)
+
+    # end prep
+
+    endline=''
+    file = opener(f_name)
+    for line in file:
+        if (re.search('^doi',line)):
+            starter=line
+            line=line.lstrip('doi = {')
+            line=line.rstrip('},\n')
+
+            endline=line
+    # print(endline)
+    return endline
+# author=author()
+# print(author)
\ No newline at end of file
diff --git a/lines/url.py b/lines/url.py
new file mode 100644
index 0000000..661c1b8
--- /dev/null
+++ b/lines/url.py
@@ -0,0 +1,35 @@
+def url():
+    """
+    encapsulate author program in a
+    function
+    """
+    # imports
+
+    import nltk
+    import re
+
+    # file
+
+    f_name="BibTex.bib"
+
+    def opener(f_name):
+        file = open(f_name, 'r', encoding="utf8")
+        return file
+
+    file=opener(f_name)
+
+    # end prep
+
+    endline=''
+    file = opener(f_name)
+    for line in file:
+        if (re.search('^url',line)):
+            starter=line
+            line=line.lstrip('url = {')
+            line=line.rstrip('},\n')
+
+            endline=line
+    # print(endline)
+    return endline
+# author=author()
+# print(author)
\ No newline at end of file
diff --git a/main.py b/main.py
index f15491d..4bfc276 100644
--- a/main.py
+++ b/main.py
@@ -70,6 +70,25 @@
 
 pages=pages.pages()
 
+
+# __________________________________
+
+import lines
+
+from lines import url
+
+url=url.url()
+
+
+# __________________________________
+
+import lines
+
+from lines import doi
+
+doi=doi.doi()
+
+
 # __________________________________
 
 import date
@@ -78,6 +97,6 @@
 
 # __________________________________
 
-reference = author + ' (' + year + ') ' + '\'' + title + '\'' + ',' + ' ' + journal + ',' + ' ' + volume + '(' + number + ')' + ' ' + 'pp. ' + pages + ', ' + 'available: ' + '[accessed: ' + date + '].'
+reference = author + ' (' + year + ') ' + '\'' + title + '\'' + ',' + ' ' + journal + ',' + ' ' + volume + '(' + number + ')' + ' ' + 'pp. ' + pages + ', ' + 'available: ' + doi + ' / ' + url + ' [accessed: ' + date + '].'
 
 print(reference)