The aorta remains visible, as a protrusion at the top centered between the two "chambers" indicated in the symbol, in some depictions of the Sacred Heart well into the 18th century, and is partly still shown today (although mostly obscured by elements such as a crown, flames, rays, or a cross) but the "hearts" suit did not have this element since the 15th century. a b "Canadian single certifications – Billie Eilish & Khalid – Lovely". Music Canada . Retrieved September 13, 2019.

Certificaciones" (in Spanish). Asociación Mexicana de Productores de Fonogramas y Videogramas . Retrieved November 19, 2019. Type Billie Eilish in the box under the ARTISTA column headingand Lovely in the box under the TÍTULO column heading.

Vinken (2001): "The change from the spherical to the scalloped form of the heart base happened more or less in train with the differing way in which the heart was held, and has dominated visual representations of the heart ever since." Murray, Robin (April 20, 2018). "Billie Eilish x Khalid Unite On 'Lovely' ". Clash . Retrieved August 2, 2020.

C. Weyers in: Stengel (ed.), Archiv für Diplomatik: Schriftgeschichte, Siegel, und Wappenkunde, Volume 54, 2008, p. 100. P. J. Vinken (2000), The Shape of the Heart: A Contribution to the Iconology of the Heart (illustrateded.), Elsevier Health Sciences, ISBN 978-0-444-82987-0Irish-charts.com – Discography Billie Eilish & Khalid". Irish Singles Chart. Retrieved November 28, 2018. Archívum – Slágerlisták – MAHASZ" (in Hungarian). Stream Top 40 slágerlista. Magyar Hanglemezkiadók Szövetsége. Retrieved November 14, 2019. a b c Boulton, Chantilly (April 26, 2018). "Billie Eilish & Khalid Are Trapped In A Glass Box For Their 'Lovely' Video". HotNewHipHop . Retrieved July 31, 2020. a b "British single certifications – Billie Eilish & Khalid – Lovely". British Phonographic Industry . Retrieved November 12, 2021. Begrand, Adrien (December 19, 2018). "The 30 Best New Musical Artists of 2018". PopMatters . Retrieved November 29, 2020.

Billie Eilish and Khalid 'Lovely' Sheet Music". Musicnotes.com. May 2018. Archived from the original on December 26, 2018 . Retrieved May 22, 2020. The combination of the heart shape and its use within the heart metaphor was developed in the end of the Middle Ages, although the shape has been used in many ancient epigraphy monuments and texts. With possible early examples or direct predecessors in the 13th to 14th century, the familiar symbol of the heart representing love developed in the 15th century, and became popular in Europe during the 16th. [10]a b c Blistein, Jon (April 19, 2018). "Hear Khalid Join Billie Eilish on Aching New Song, 'Lovely' ". Rolling Stone. Archived from the original on November 29, 2018 . Retrieved July 31, 2020. a b "ARIA Charts – Accreditations – 2023 Singles" (PDF). Australian Recording Industry Association . Retrieved July 7, 2023. A common emoticon for the heart is <3. In Unicode several heart symbols are available in text format: