Website/Catalog  (16 Jul 2014)  
 
Registered Name: 'Mattjo'
ARS Approved Exhibition Name: Snowman
HT, w, 1984, John Mattock, Ltd.; flowers large, dbl., moderate fragrance; foliage large, dark, semi-glossy; upright, bushy growth. [(Peer Gynt × Isis) × Lady Seton]. Introductions: 1983

Book  (19 Apr 2000)  Page(s) 352.  
 
'MATtjo', HT, w, 1983; (Snowman); description; ((Peer Gynt X Isis) X Lady Seton); Mattock, John, Ltd.

Book  (Apr 1993)  Page(s) 559.  
 
Snowman HT , w , 1983 , ( MATtjo ) ; ( Peer Gynt × Isis ) × Lady Seton ; Mattock , John . Flowers white , dbl . ( 40+ petals ) , large ; fragrant , foliage large , dark , semi - glossy , upright , bushy .

Website/Catalog  (1989)  Page(s) 88.  
 
Showman ( Mattjo ) HT Mattock 1983 MR9

Book  (1988)  Page(s) 158(photo)-159.  Includes photo(s).
 
Showman ( Mattjo ) A Hybrid Tea raised by Mattock in 1983. Parentage : not yet available .

Book  (1984)  Page(s) 172.  
 
Showman ( Mattjo ) ; HT ; ( John Mattock ; John Mattock Ltd ; 1983 ) ; ( Peer Gynt x Isis ) x Lady Seton ; large blooms ....

Book  (1984)  Page(s) 115.  
 
Angela Pawsey. New Varieties 1983.
'Showman' (Mattjo). Mattock. LF of exhibition size. White. TGC. Available 1983 Mattock, A. Higgs.

Book  (1981)  Page(s) 49.  
 
E. F. Allen. Awards to new Rose Seedlings in Great Britain in 1980.
Trial Ground Certificate. 'JM335-74 (Seedling x 'Lady Seton'). An impressive, white flowered H.T. by Mattock of Oxford, with very good foliage and considerable vigour. The flowers have a very strong scent.