A. M. H. Hasan, “Soft Pre-Open Sets In Soft Bitopological Spaces”, ASRJETS-Journal, vol. 26, no. 4, pp. 42–53, Dec. 2016, Accessed: Dec. 16, 2025. [Online]. Available: https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/2059