BibTeX:
@incollection{Various,
  author = {Various},
  title = {Amatu'l-Bahá Rúhíyyih Khánum in one of her memories says that she was once in a…},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/teaching},
}

APA:
Various. Amatu'l-Bahá Rúhíyyih Khánum in one of her memories says that she was once in a…. In *bahaistories.com archive*.

MLA:
Various. "Amatu'l-Bahá Rúhíyyih Khánum in one of her memories says that she was once in a…." *bahaistories.com archive*, n.d..

Chicago:
Various. "Amatu'l-Bahá Rúhíyyih Khánum in one of her memories says that she was once in a…." In *bahaistories.com archive*, n.d..