¿Cual es el formato para citar un libro, un articulo y una pagina web?

Alimitation on the president’s power to appoint ambassadors is that

How has the elimination of trade barriers affected the movement of goods among member countries of the european union? a. member countries are able to produce all the goods they need. b. goods can move freely among member countries. c. member countries no longer need to trade with countries outside the eu. d. larger countries are able to import more goods than smaller ones.

Experiment to investigate effect of medication on levels of stress in males and females. dependant variable?