Khalifa, H., Ahmed, A. A., Abusaediyah, A., Yousuf, A. and Grimida, S. (2017) “GAS CHROMATOGRAPHY - MASS SPECTROMETRY (GC-MS) IN ORGANIC GEOCHEMICAL INVESTIGATION OF CRUDE OILS FROM KIKINDA AND VELEBIT FIELDS IN SERBIA”, International Journal of Research -GRANTHAALAYAH, 5(6), pp. 550–560. doi: 10.29121/granthaalayah.v5.i6.2017.2073.