diff --git a/docs/refguide.xml b/docs/refguide.xml
index f4fbb9251..87bf8a458 100644
--- a/docs/refguide.xml
+++ b/docs/refguide.xml
@@ -1575,7 +1575,7 @@ way.
enables version detection among other things. A paper documenting
the workings, usage, and customization of version detection is
available at .
+ url="http://nmap.org/book/vscan.html" />.
When Nmap receives responses from a service but cannot match
them to its database, it prints out a special fingerprint and
@@ -1765,7 +1765,7 @@ way.
A paper documenting the workings, usage, and customization
of OS detection is available at .
+ url="http://nmap.org/book/osdetect.html" />.
OS detection is enabled and controlled with the following options:
@@ -1852,7 +1852,7 @@ way.
network handling with the versatility of the lightweight scripting language
Lua, thus providing innumerable
opportunities. A more extensive documentation of the NSE (including its
- API) can be found at: . The
+ API) can be found at: . The
target of the NSE is to provide Nmap with a flexible infrastructure for
extending its capabilities and offering its users a simple way of creating
customized tests. Uses for the NSE include (but definitely are not limited
@@ -1925,7 +1925,7 @@ way.
you are not required to follow this for the moment, this may change in the
future. Nmap will issue a warning if a file has any other extension.
More extensive documentation on the NSE, including a description of its API
- can be found at .
+ can be found at .