1) Put the text in QUOTE with the QUOTE tags
Quote example
2) Specify the author (if possible) and especially the source with a link http://ww...
Example: https://www.econologie.com/forums/post36566.html#36566
ps: beware of reproduction and copyright rights for certain texts. For example often, sites allow to resume the introduction and the 1st lines of the article. Ask before proceeding.