AUTHOR=Dunlop M. W. , Fu H.-S. , Shen C. , Tan X. , Dong X.-C. , Yang Y.-Y. , Robert P. , Escoubet C. P. TITLE=Curlometer and gradient techniques: past and future applications JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=11 YEAR=2024 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2024.1422341 DOI=10.3389/fspas.2024.1422341 ISSN=2296-987X