The International Rhododendron register (1958).
Royal Horticultural Society (Great Britain)
London : The Society,
1988-
Supplements no. [1-26] incorporated within the yearbooks; no. [27] published separately as: Additions to the International Rhododendron register 1986-87.
Rhododendrons
Ericaceae.
Rhododendrons with magnolias and camellias