https://www.pnas.org/content/pnas/23/12/615.full.pdf @@ Pauling & Sturdivant: cyameluric acid etc.

http://www.arkat-usa.org/get-file/19834/ @@ Akorta: theoretical study of resonance forms

https://edoc.ub.uni-muenchen.de/25071/1/Kessler_Fabian_K.pdf @@ Kessler: PhD thesis on C/N/H compounds

https://pubs.acs.org/doi/pdf/10.1021/ja01267a056 @@ Redemann & Lucas: Ionization constants of cyameluric acid

https://iopscience.iop.org/article/10.1070/RC1964v033n07ABEH001443/pdf Finkel'shtein & Spiridonova: Review of derivatives of heptazine

https://onlinelibrary.wiley.com/doi/epdf/10.1002/1521-3935%2820010101%29202%3A1%3C19%3A%3AAID-MACP19%3E3.0.CO%3B2-G @@ Komatsu: The First Synthesis and Characterization of Cyameluric High Polymers

https://pubs.rsc.org/en/content/articlelanding/2001/jm/b005982j/ @@ Komatsu & Nakamura: Polycondensation/pyrolysis of ???

https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=PASCAL7960244305 @@ Slisarenko: DOSAGE POLAROGRAPHIQUE DE L'ACIDE CYAMELLURIQUE ET DU MELEM