correct citation for external source

Signed-off-by: Stefan Cyliax <stefan.cyliax@asam.net>

Author: Stefan Cyliax

osi_featuredata.proto

@@ -453,15 +453,19 @@ message LidarDetection
     // Echo pulse width of the detection's echo.
     // Several sensors output an echo pulse width instead of an intensity for each individual detection.
     // The echo pulse is measured in m and measures the extent of the object parts or atmospheric particles that produce the echo.
-    // Fig. 7 shows an example where the two echos are reflected from the edges A-B and C-D. For more details, see [Rosenberger et al.](https://link.springer.com/content/pdf/10.1007/s41104-020-00066-x.pdf).
-    // Fig. 8 shows how the echo pulse width is measured as the range between the rising edge and the falling edge that crosses the intensity threshold. For more details, see [Rosenberger et al.](https://link.springer.com/content/pdf/10.1007/s41104-020-00066-x.pdf).
+    // \note For more details see [1] Fig. 7 and 8.
+    // \note Fig. 7 shows an example where the two echos are reflected from the edges A-B and C-D.
+    // \note Fig. 8 shows how the echo pulse width is measured as the range between the rising edge and the falling edge that crosses the intensity threshold.
     //
     // Unit: m
     //
     // \rules
     // is_greater_than_or_equal_to: 0
     // \endrules
     //
+    // \par Reference:
+    // [1] Rosenberger, P., Holder, M.F., Cianciaruso, N. et al. (2020). <em>Sequential lidar sensor system simulation: a modular approach for simulation-based safety validation of automated driving</em> Automot. Engine Technol. 5, Fig 7, Fig 8. Retrieved May 10, 2021, from https://doi.org/10.1007/s41104-020-00066-x
+    //
     optional double echo_pulse_width = 11;
 }