T. A. Herawan, Y. H. Chrisnanto, and A. I. Hadiana, “KLASIFIKASI HELPDESK UNIVERSITAS JENDERAL ACHMAD YANI MENGGUNAKAN CONCEPT FREQUENCY-INVERSE DOCUMENT FREQUENCY (CF-IDF) DAN K-NEAREST NEIGHBORS (K-NN)”, SNST, vol. 1, no. 1, Sep. 2016.