Zulkarnain, I. 2009. Geochemical Signature of Mesozoic Volcanic and Granitic Rocks in Madina Regency Area, North Sumatra, Indonesia, and its Tectonic Implication. Indonesian Journal on Geoscience. 4, 2 (Jun. 2009), 117–131. DOI:https://doi.org/10.17014/ijog.4.2.117-131.