Yes they will all need to be listed in the References List and, in the Diss itself, where you make either detailed or generalised statements about the data from those sources, in-text citations will be needed.
Even if you didn't mention some specifically in the Diss but you may have said something along the lines of "I conducted research and from a sample of 40 studies found that..." , the marker wiill want to know what 40 studies were sampled.