Lumban Gaol, Rikki, AND 		Karo Karo, Pelliyezer.
" MANAJEMEN BAHASA ASING BAGI STAF FRONT OFFICE MENGHADAPI PASAR WISATAWAN MANCANEGARA" <em>Jurnal Darma Agung</em> [Online], Volume 31 Number 4 (2 September 2023)