Many of the texts on the Cold War in the library include some coverage of the Marshall Plan. The Cold War books listed below are those which cover the Marshall Plan in more detail.
For an overview of your topic use the encyclopedias in the Reference Collection.The following book provides a summary of the Marshall Plan:
Viewpoint essays on the topic below can be found in the History in Dispute series which is kept in the Reference section. The series is also available online through the Gale World History database.
"What were the true motivations behind the Marshall Plan?" Volume 1: 173-179.
Use the online databases to find articles from journals. Start with JSTOR through the State Library, and then try the other State Library databases which are listed in the box.
Also make sure that you search the GGS subscription database: Gale World History in Context.