diff --git a/papers/commands/__init__.py b/papers/commands/__init__.py
index f20dd9d..179e7ca 100644
--- a/papers/commands/__init__.py
+++ b/papers/commands/__init__.py
@@ -1,12 +1,12 @@
 import init_cmd
 import add_cmd
 import list_cmd
+import open_cmd
+import websearch_cmd
 # import import_cmd
 # import export_cmd
 # import edit_cmd
 # import remove_cmd
-# import open_cmd
-# import websearch_cmd
 # import tag_cmd
 # import attach_cmd
 # import update_cmd
diff --git a/papers/commands/open_cmd.py b/papers/commands/open_cmd.py
index 670899e..3807cb2 100644
--- a/papers/commands/open_cmd.py
+++ b/papers/commands/open_cmd.py
@@ -1,11 +1,10 @@
 import subprocess
 
 from .. import repo
-from ..paper import NoDocumentFile
 from ..configs import config
 from ..uis import get_ui
 from .. import color
-from .helpers import add_references_argument, parse_reference
+#from .helpers import add_references_argument, parse_reference
 
 
 def parser(subparsers):
@@ -13,7 +12,8 @@ def parser(subparsers):
             help='open the paper in a pdf viewer')
     parser.add_argument('-w', '--with', dest='with_command', default=None,
             help='command to use to open the document file')
-    add_references_argument(parser, single=True)
+    parser.add_argument('citekey',
+            help='citekey of the paper')
     return parser
 
 
@@ -21,23 +21,24 @@ def command(args):
 
     ui = get_ui()
     with_command = args.with_command
-    reference = args.reference
+    citekey = args.citekey
 
     rp = repo.Repository(config())
-    key = parse_reference(rp, reference)
-    paper = rp.get_paper(key)
+    paper = rp.pull_paper(citekey)
     if with_command is None:
         with_command = config().open_cmd
+
+    if paper.docpath is None:
+        ui.error('No document associated with the entry {}.'.format(
+                 color.dye(citekey, color.citekey)))
+        ui.exit()
+
     try:
-        filepath = paper.get_document_path()
+        docpath = rp.databroker.real_docpath(paper.docpath)
         cmd = with_command.split()
-        cmd.append(filepath)
+        cmd.append(docpath)
         subprocess.Popen(cmd)
-        ui.print_('{} opened.'.format(color.dye(filepath, color.filepath)))
-    except NoDocumentFile:
-        ui.error('No document associated with the entry {}.'.format(
-                 color.dye(key, color.citekey)))
-        ui.exit()
+        ui.print_('{} opened.'.format(color.dye(docpath, color.filepath)))
     except OSError:
         ui.error("Command does not exist: %s." % with_command)
         ui.exit(127)
diff --git a/papers/papers_cmd.py b/papers/papers_cmd.py
index ea0c67b..58e0f6c 100644
--- a/papers/papers_cmd.py
+++ b/papers/papers_cmd.py
@@ -16,12 +16,12 @@ CORE_CMDS = collections.OrderedDict([
         ('init',        commands.init_cmd),
         ('add',         commands.add_cmd),
         ('list',        commands.list_cmd),
+        ('open',        commands.open_cmd),
+        ('websearch',   commands.websearch_cmd),
         # ('import',      commands.import_cmd),
         # ('export',      commands.export_cmd),
         # ('edit',        commands.edit_cmd),
         # ('remove',      commands.remove_cmd),
-        # ('open',        commands.open_cmd),
-        # ('websearch',   commands.websearch_cmd),
         # ('tag',         commands.tag_cmd),
         # ('attach',      commands.attach_cmd),
         # ('update',      commands.update_cmd),