How to find specific content on a site with wget_om?

Question

Wget

It is required to find certain content and display in the txt document all urls containing this element in the address I
execute the command

wget -r -q -O- http://www.undu.ru/ | grep 'uploads' |

Answer 1

$ wget -r -q -O- http://www.undu.ru/ |grep 'a href'| --append-output=log.txt

tried like this, negative result, digging further