<https://www.gamesbids.com/forums/topic/24256-rio-de-janeiro-2016-ceremonies/>
<http://schema.org/text>
"Sorry, what I meant was the layers of soil, gravel, sand etc. beneath the turf which make the pitch good to play on, and which would need to be protected from too much compression etc. \n"
<https://www.gamesbids.com/forums/topic/24256-rio-de-janeiro-2016-ceremonies/page/35/?tab=comments#comment-496941>