diff --git a/FourmiCrawler/sources/ChemSpider.py b/FourmiCrawler/sources/ChemSpider.py
index 6ca5382..b4bf6f0 100644
--- a/FourmiCrawler/sources/ChemSpider.py
+++ b/FourmiCrawler/sources/ChemSpider.py
@@ -277,8 +277,8 @@ class ChemSpider(Source):
             log.msg('ChemSpider found multiple substances, taking first '
                     'element', level=log.DEBUG)
         csid = csids[0]
-        structure_url = self.website[:-1] + self.structure % csid
-        extendedinfo_url = self.website[:-1] + self.extendedinfo % csid
+        structure_url = self.website[:-2].replace("\\", "") + self.structure % csid
+        extendedinfo_url = self.website[:-2].replace("\\", "") + self.extendedinfo % csid
         log.msg('chemspider URL: %s' % structure_url, level=log.DEBUG)
         return [Request(url=structure_url,
                         callback=self.parse),
diff --git a/FourmiCrawler/sources/NIST.py b/FourmiCrawler/sources/NIST.py
index 4ad93f5..691b062 100644
--- a/FourmiCrawler/sources/NIST.py
+++ b/FourmiCrawler/sources/NIST.py
@@ -164,7 +164,7 @@ class NIST(Source):
             extra_data_url = tr.xpath('td[last()][a="Individual data points"]'
                                       '/a/@href').extract()
             if extra_data_url:
-                request = Request(url=self.website[:-1] + extra_data_url[0],
+                request = Request(url=self.website[:-2].replace("\\", "") + extra_data_url[0],
                                   callback=self.parse_individual_datapoints)
                 results.append(request)
                 continue
diff --git a/FourmiCrawler/sources/PubChem.py b/FourmiCrawler/sources/PubChem.py
index 5947e54..0768612 100644
--- a/FourmiCrawler/sources/PubChem.py
+++ b/FourmiCrawler/sources/PubChem.py
@@ -51,7 +51,7 @@ class PubChem(Source):
             self._spider.get_synonym_requests(synonym)
         log.msg('Raw synonyms found: %s' % raw_synonyms, level=log.DEBUG)
 
-        n = re.search(r'cid=(\d+)',response.url)
+        n = re.search(r'cid=(\d+)', response.url)
         if n:
             cid = n.group(1)
         log.msg('cid: %s' % cid, level=log.DEBUG)   #getting the right id of the compound with which it can reach