Oxford Reference is a compilation of hundreds of individual reference tools, published by Oxford University Press, combined into one searchable database. We often have the individual print equivalents if you decide to read in depth from one tool. But, to start with, search Oxford Reference online to find some general information.
Results include entries on umbrellas from A Dictionary of English Folklore and The Oxford Dictionary of the Renaissance. These could provide contexts for studying the topic. They provide histories and meanings of the term. Also look at the "Bibliographies" or "Further Readings" of the entries from these sources.
Encyclopedia of Semiotics(Paul Boussiac. OUP. 1998) - is also included within Oxford Reference Online includes this scholarly, encyclopedia on Semotics
This tool is different than a regular encyclopedia because the goal is to give you an overview of what has been written on the topic, thus, it is called Oxford Bibliographies(not Oxford Reference). This tool provides some of the best literature review information on a topic all in one place.
For example: search "semiotics"
Entries are written by scholars, including Marcel Danesi. His entry provides names of:
Seminal Journals in the field
Branches: Verbal, Visual, Internet, Non-Verbal, etc.
Non-verbal: gestures (many students use gestures): ie. Praying hands; peace sign
By browsing, you may find a branch that fits your topic or you might find a topic by looking at the branches