Piperonal (English Wikipedia)

Gilla, G.; Anumula, R.R.; Aalla, S.; Vurimidi, H. & Ghanta, M.R. (2013). "Synthesis and characterization of related substances and metabolite of tadalafil, a PDE-5 inhibitor" (PDF). Organic Communications. 6 (1): 12–22. Archived (PDF) from the original on 2018-10-24. Retrieved 2015-01-21.

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"Essential oils". Archived from the original on 2019-12-23. Retrieved 2012-09-02.

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The Force of Fashion in Politics and Society: Global Perspectives from Early Modern to Contemporary Times By Beverly Lemire ISBN 9781409404927

doi.org (Global: 2^nd place; English: 2^nd place)

Panten, Johannes; Surburg, Horst (2016). "Flavors and Fragrances, 3. Aromatic and Heterocyclic Compounds". Ullmann's Encyclopedia of Industrial Chemistry. pp. 1–45. doi:10.1002/14356007.t11_t02. ISBN 978-3-527-30673-2.
Fatiadi, Alexander & Schaffer, Robert (1974). "An Improved Procedure for Synthesis of DL-4-Hydroxy-3-methoxymandelic Acid (DL-"Vanillyl"-mandelic Acid, VMA)". Journal of Research of the National Bureau of Standards Section A. 78A (3): 411–412. doi:10.6028/jres.078A.024. PMC 6742820. PMID 32189791.
Nwaukwa, Stephen; Keehn, Philip (1982). "Oxidative cleavage of α-diols, α-diones, α-hydroxy-ketones and α-hydroxy- and α-keto acids with calcium hypochlorite [Ca(OCl)₂]". Tetrahedron Letters. 23 (31): 3135–3138. doi:10.1016/S0040-4039(00)88578-0.
Bonthrone, W. & Cornforth, J. (1969). "The methylenation of catechols". Journal of the Chemical Society (9): 1202–1204. doi:10.1039/J39690001202.
Yamada, Shun-Ichi; Fujii, Tozo; Shioiri, Takayuki (1962). "Studies on Optically Active Amino Acids. I. Preparation of 3-(3, 4-Methylenedioxyphenyl)-D-, and -L-alanine". Chemical & Pharmaceutical Bulletin. 10 (8): 680–688. doi:10.1248/cpb.10.680. PMID 14002245.
Winn, Martin; von Geldern, Thomas W.; Opgenorth, Terry J.; Jae, Hwan-Soo; Tasker, Andrew S.; Boyd, Steven A.; Kester, Jeffrey A.; Mantei, Robert A.; Bal, Radhika; Sorensen, Bryan K.; Wu-Wong, Jinshyun R.; Chiou, William J.; Dixon, Douglas B.; Novosad, Eugene I.; Hernandez, Lisa; Marsh, Kennan C. (1996). "2,4-Diarylpyrrolidine-3-carboxylic AcidsPotent ETASelective Endothelin Receptor Antagonists. 1. Discovery of A-127722". Journal of Medicinal Chemistry. 39 (5): 1039–1048. doi:10.1021/jm9505369. ISSN 0022-2623. PMID 8676339.

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Regulation (EC) No 273/2004 of the European Parliament and of the Council of 11 February 2004 on drug precursors

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Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-15.

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Fatiadi, Alexander & Schaffer, Robert (1974). "An Improved Procedure for Synthesis of DL-4-Hydroxy-3-methoxymandelic Acid (DL-"Vanillyl"-mandelic Acid, VMA)". Journal of Research of the National Bureau of Standards Section A. 78A (3): 411–412. doi:10.6028/jres.078A.024. PMC 6742820. PMID 32189791.
Yamada, Shun-Ichi; Fujii, Tozo; Shioiri, Takayuki (1962). "Studies on Optically Active Amino Acids. I. Preparation of 3-(3, 4-Methylenedioxyphenyl)-D-, and -L-alanine". Chemical & Pharmaceutical Bulletin. 10 (8): 680–688. doi:10.1248/cpb.10.680. PMID 14002245.
Winn, Martin; von Geldern, Thomas W.; Opgenorth, Terry J.; Jae, Hwan-Soo; Tasker, Andrew S.; Boyd, Steven A.; Kester, Jeffrey A.; Mantei, Robert A.; Bal, Radhika; Sorensen, Bryan K.; Wu-Wong, Jinshyun R.; Chiou, William J.; Dixon, Douglas B.; Novosad, Eugene I.; Hernandez, Lisa; Marsh, Kennan C. (1996). "2,4-Diarylpyrrolidine-3-carboxylic AcidsPotent ETASelective Endothelin Receptor Antagonists. 1. Discovery of A-127722". Journal of Medicinal Chemistry. 39 (5): 1039–1048. doi:10.1021/jm9505369. ISSN 0022-2623. PMID 8676339.

ncbi.nlm.nih.gov

Fatiadi, Alexander & Schaffer, Robert (1974). "An Improved Procedure for Synthesis of DL-4-Hydroxy-3-methoxymandelic Acid (DL-"Vanillyl"-mandelic Acid, VMA)". Journal of Research of the National Bureau of Standards Section A. 78A (3): 411–412. doi:10.6028/jres.078A.024. PMC 6742820. PMID 32189791.

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The Good Scents Company database entry for Heliotropin Archived 2020-08-01 at the Wayback Machine

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"List I and II Regulated Chemicals - Alphabetical Order" (PDF). www.deadiversion.usdoj.gov. DEA Diversion - US DOJ. 19 September 2025. p. 2. Retrieved 21 September 2025.

web.archive.org (Global: 1^st place; English: 1^st place)

Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-15.
Gilla, G.; Anumula, R.R.; Aalla, S.; Vurimidi, H. & Ghanta, M.R. (2013). "Synthesis and characterization of related substances and metabolite of tadalafil, a PDE-5 inhibitor" (PDF). Organic Communications. 6 (1): 12–22. Archived (PDF) from the original on 2018-10-24. Retrieved 2015-01-21.
"Essential oils". Archived from the original on 2019-12-23. Retrieved 2012-09-02.
The Good Scents Company database entry for Heliotropin Archived 2020-08-01 at the Wayback Machine

worldcat.org (Global: 5^th place; English: 5^th place)

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Winn, Martin; von Geldern, Thomas W.; Opgenorth, Terry J.; Jae, Hwan-Soo; Tasker, Andrew S.; Boyd, Steven A.; Kester, Jeffrey A.; Mantei, Robert A.; Bal, Radhika; Sorensen, Bryan K.; Wu-Wong, Jinshyun R.; Chiou, William J.; Dixon, Douglas B.; Novosad, Eugene I.; Hernandez, Lisa; Marsh, Kennan C. (1996). "2,4-Diarylpyrrolidine-3-carboxylic AcidsPotent ETASelective Endothelin Receptor Antagonists. 1. Discovery of A-127722". Journal of Medicinal Chemistry. 39 (5): 1039–1048. doi:10.1021/jm9505369. ISSN 0022-2623. PMID 8676339.

Piperonal (English Wikipedia)

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