diff --git a/iocp.py b/iocp.py
index 9968cc2..65f0fb2 100755
--- a/iocp.py
+++ b/iocp.py
@@ -47,10 +47,8 @@
     import ConfigParser
 
 # Import optional third-party libraries
-IMPORTS = []
 try:
     from PyPDF2 import PdfFileReader
-    IMPORTS.append('pypdf2')
 except ImportError:
     pass
 try:
@@ -59,17 +57,14 @@
     from pdfminer.converter import TextConverter
     from pdfminer.pdfinterp import PDFPageInterpreter
     from pdfminer.layout import LAParams
-    IMPORTS.append('pdfminer')
 except ImportError:
     pass
 try:
     from bs4 import BeautifulSoup
-    IMPORTS.append('beautifulsoup')
 except ImportError:
     pass
 try:
     import requests
-    IMPORTS.append('requests')
 except ImportError:
     pass
 
@@ -104,11 +99,11 @@ def __init__(self, patterns_ini=None, input_format='pdf', dedup=False, library='
 
         self.library = library
         if input_format == 'pdf':
-            if library not in IMPORTS:
+            if library not in sys.modules:
                 e = 'Selected PDF parser library not found: %s' % (library)
                 raise ImportError(e)
         elif input_format == 'html':
-            if 'beautifulsoup' not in IMPORTS:
+            if 'beautifulsoup' not in sys.modules:
                 e = 'HTML parser library not found: BeautifulSoup'
                 raise ImportError(e)
 
@@ -269,7 +264,7 @@ def parse_html(self, f, fpath):
     def parse(self, path):
         try:
             if path.startswith('http://') or path.startswith('https://'):
-                if 'requests' not in IMPORTS:
+                if 'requests' not in sys.modules:
                     e = 'HTTP library not found: requests'
                     raise ImportError(e)
                 headers = { 'User-Agent': 'Mozilla/5.0 Gecko Firefox' }
diff --git a/output.py b/output.py
index d71c92c..0503774 100644
--- a/output.py
+++ b/output.py
@@ -31,7 +31,7 @@ def print_error(self, fpath, exception):
 
 class OutputHandler_csv(OutputHandler):
     def __init__(self):
-        self.csv_writer = csv.writer(sys.stdout, delimiter = '\t')
+        self.csv_writer = csv.writer(sys.stdout, delimiter = '\t', quoting=csv.QUOTE_NONNUMERIC)
 
     def print_match(self, fpath, page, name, match):
         self.csv_writer.writerow((fpath, page, name, match))