Q. I am looking for information about the history of reflecting pools in landscape architecture and gardens. I am having trouble finding resources.

There is a very useful subject heading to use for locating books in HOLLIS, the Harvard library catalog: "water in landscape architecture" .

You might also want to consult the following book in collection:

Encyclopedia of gardens: history and design
Call Number: Reference SB465 .E63 2001

For articles on this topic, you might consider a cross search of the Avery Index to Architectural Periodicals (1930-)  (EBSCO),Art Index Retrospective (1929-1984), and Art Full Text (1983-) - all are available from EBSCO.