Nouman, A., Bajwa, K. B., Sablatnig, R., Chatzichristofis, S. A., Iqbal, Z., Rashid, M., & Habib, H. A. (2016). A Novel Image Retrieval Based on Visual Words Integration of SIFT and SURF. PLoS ONE, 11(6), e0157428. https://doi.org/10.1371/journal.pone.0157428