As this is an English forum, people from all around the world use it to discuss about the usage of this particular VLE in the education.
If you are focused on exploring the usage of 5 selected virtual learning environments in your country, the samples collected this way will not provide the kind of specific information that would be most useful to you.
In case you actually do need to collect this kind of samples, maybe to compare them with the results collected in your country (to increase the awareness,) then many people using this forum will probably help.
Рegards,
Saša Stamenković