price space as a dual of commodity space I often see papers in economic theory mentioning a duality between the price space and the commodity space. I think they refer to duality of vector spaces. I.e, the commodity space is a vector space, a price system is a linear functional over the commodity space (assigning a value to each bundle), and so the space of all possible price systems  is the dual of the commodity space.

Is there a standard reference that explains this duality in more detail?
If you want to see a nice usage of duality in economics, in Mas-Colell, Whinston, and Green  there's a nice section on duality in the second or third chapter when talking about Hicksian demand. The treatment is pretty straightforward if the consumption space is real and has a finite dimension. I think understanding that basic usage of duality is illustrative of its general utility.

If the idea is to understand what duality is and how it operates, I think Conway is a great book. 

(Just undergrad here, hope I'm not mixing up topics).