diff --git a/math/double_factorial.cpp b/math/double_factorial.cpp
index 26b90f356..37bd2052a 100644
--- a/math/double_factorial.cpp
+++ b/math/double_factorial.cpp
@@ -1,5 +1,7 @@
 /**
  * @file
+ * @brief Compute double factorial: \f$n!!\f$
+ *
  * Double factorial of a non-negative integer n, is defined as the product of
  * all the integers from 1 to n that have the same parity (odd or even) as n.
  * <br/>It is also called as semifactorial of a number and is denoted by
@@ -9,7 +11,8 @@
 #include <cassert>
 #include <iostream>
 
-/// Compute double factorial using iterative method
+/** Compute double factorial using iterative method
+ */
 uint64_t double_factorial_iterative(uint64_t n) {
     uint64_t res = 1;
     for (uint64_t i = n;; i -= 2) {
@@ -19,8 +22,9 @@ uint64_t double_factorial_iterative(uint64_t n) {
     return res;
 }
 
-/// Compute double factorial using resursive method.
-//  <br/>Recursion can be costly for large numbers.
+/** Compute double factorial using resursive method.
+ * <br/>Recursion can be costly for large numbers.
+ */
 uint64_t double_factorial_recursive(uint64_t n) {
     if (n <= 1) return 1;
     return n * double_factorial_recursive(n - 2);