wdata-format-concept.md

@@ -8,7 +8,9 @@
 * Data is convenient for copying between computing systems.  
 * It allows for easy extraction/copying of selected variables.
 
-**W-data** format **is not a library**. It is only a **concept**. It specifies how the data should be saved or read. It means that you do not need to use any external libraries to be able to read or write. It is sufficient to use standard I/O functions to work with this format. We provide within this repository libraries written in C or in python just for convenience. 
+**W-data** format **is not a library**. It is only a **concept**. It specifies how the data should be saved or read. It means that you do not need to use any external libraries to be able to read or write. It is sufficient to use standard I/O functions to work with this format. We provide within this repository libraries written in C or in python just for convenience. The example code demonstrating this concept can be found here [
+c-examples
+/example-write-low-level.c](https://gitlab.fizyka.pw.edu.pl/wtools/wdata/-/blob/master/c-examples/example-write-low-level.c). The concept is described below. 
 
 # W-data format concept  
 The data set will consist of a set of files, for example: