The word(s) "duly" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) He replied: "The knowledge of that is with my Lord, duly recorded: my Lord never errs, nor forgets,-

(سورة طه, Taa-Haa, Chapter #20, Verse #52)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) Say: "The Angel of Death, put in charge of you, will (duly) take your souls: then shall ye be brought back to your Lord."

(سورة السجدة, As-Sajda, Chapter #32, Verse #11)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(3) The Companions of the Wood, and the People of Tubba'; each one (of them) rejected the messengers, and My warning was duly fulfilled (in them).

(سورة ق, Qaaf, Chapter #50, Verse #14)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)