"Open day". Collins English Dictionary - Complete & Unabridged 10th Edition. HarperCollins. Diarsipkan dari versi asli tanggal 2017-10-26. Diakses tanggal 25 January 2015.
"Open day". Collins English Dictionary - Complete & Unabridged 10th Edition. HarperCollins. Diarsipkan dari versi asli tanggal 2017-10-26. Diakses tanggal 25 January 2015.