That indispensable resource for English Parish Register transcriptions has been enhanced to provide citations in a number of formats, one of which is WikiTree.
FreeREG, FreeBMD, and FreeCEN are free transcriptions of English Parish Registers, Civil Birth Marriage and Death Registrations and the English Census. Not everything has been transcribed and they are always looking for volunteers to help with the work.
The URL's are www.freereg.org.uk, www.freebmd.org.uk, www.freecen.org.uk.
Enjoy!