None of the site you give meets Wikipedia requirements for references Please see WPV  the editor wishing to add the material is responsible for supplying a credable reference In  this case a historical work showing that the symbol was used by the Golden Dawn and NOT some successor organization Stella Matutina modern GD reconstruction etc That is a book reference with a page number so other editors can verify it Per WPV any editor may remove uncited additions The burden of proof is on the editor who wishes to make the addition In  any case it doesnt belong at the top of the article