Sanjaya, Gregorius Magnus Mega, et al. “Analisis Kekaburan Cipherteks Hasil Perulangan Enkripsi Vigenere Dan Transposisi Columnar Cipher”. Prosiding Seminar Nasional Sains Teknologi Dan Inovasi Indonesia (SENASTINDO), vol. 2, Nov. 2020, pp. 293-8, https://aau.e-journal.id/senastindo/article/view/115.