Wikipedia, engl.
https://en.wikipedia.org/wiki/Shirley_Hibberd
Dictionary of National Biography 26 (1891), S. 342-343
https://archive.org/stream/dictionarynatio46stepgoog#page/n354
https://en.wikisource.org/wiki/Hibberd,_Shirley_%28DNB00%29
Guildhall Library blog
https://guildhalllibrarynewsletter.wordpress.com/2015/04/24/diy-in-the-v...
The American Garden 12 (1891), S. 44-45
https://books.google.com/books?id=9tofAQAAIAAJ&pg=PA44
Journal of Horticulture and Practical Gardening 21 (1891), S. 441-442
https://books.google.com/books?id=RflIAAAAYAAJ&pg=PA441