Portrait by Thomas Kirkby, c. 1828
Recommended Reference sources:
See this very substantial overview in Wikipedia.
Burning Wycliffe's bones, from Foxe's Book of Martyrs (1563)
Here's a link to Books on Wycliffe and his theology available at Luther Sem; many others available by interlibrary loan in Minnesota (Minitex)
Also consult the following databases for helpful articles or abstracts on Wycliffe (both JSTOR and Open Access Theological Library have hundreds of book chapters or articles on Wycliffe see this JSTOR link for example).