diff --git a/src/core/raw.c b/src/core/raw.c
index 33f3a516..5033af41 100644
--- a/src/core/raw.c
+++ b/src/core/raw.c
@@ -2,8 +2,8 @@
  * @file
  * Implementation of raw protocol PCBs for low-level handling of
  * different types of protocols besides (or overriding) those
- * already available in lwIP.
- *
+ * already available in lwIP.\n
+ * See also @ref rawapi
  */
 
 /*
diff --git a/src/core/tcp.c b/src/core/tcp.c
index b9d3ad79..8962979d 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -4,8 +4,9 @@
  *
  * This file contains common functions for the TCP implementation, such as functinos
  * for manipulating the data structures and the TCP timer functions. TCP functions
- * related to input and output is found in tcp_in.c and tcp_out.c respectively.
+ * related to input and output is found in tcp_in.c and tcp_out.c respectively.\n
  *
+ * See also @ref rawapi
  */
 
 /*
diff --git a/src/core/udp.c b/src/core/udp.c
index 548ec115..217648b7 100644
--- a/src/core/udp.c
+++ b/src/core/udp.c
@@ -1,7 +1,8 @@
 /**
  * @file
- * User Datagram Protocol module
+ * User Datagram Protocol module\n
  *
+ * See also @ref rawapi
  */
 
 /*
diff --git a/src/include/lwip/sys.h b/src/include/lwip/sys.h
index 2659726b..380d03b0 100644
--- a/src/include/lwip/sys.h
+++ b/src/include/lwip/sys.h
@@ -1,6 +1,7 @@
 /**
  * @file
- * OS abstraction layer
+ * OS abstraction layer\n
+ * See also @ref sys
  */
 
 /*