Book  (Oct 2001)  Page(s) 394.  Includes photo(s).

Magazine  (28 Jul 1937)  Page(s) 56.  
 
TWENTY BEST LARGE-FLOWERED HYBRIDS OBTAINABLE IN THIS COUNTRY
William Kennett, deep lavender, Lanuginosa Type
All bloom on new wood except Belle of Woking and Sir Garnet Wolseley

Website/Catalog  (1924)  Page(s) 107.  
 
William Kennett (Jackmani). Bleu lav. foncé.

Website/Catalog  (1912)  Page(s) 78.  
 
Summer and Autumn Clematis.
In bloom from July to October.
These flower upon the wood of the current year's growth, and should therefore be pruned to five or six eyes.  
William Kennett, large deep blue, changing to lavender...  1s. 6d.

Book  (1906)  Page(s) 53.  
 
Principal garden varieties of Clematis:
Lanuginosa type. (July to October.)
William Kennett... Deep lavender.

Magazine  (24 Nov 1900)  Page(s) 90.  
 
Die Firma Simon Louis frères, Plantières bei Metz, hatte Neuheiten und seltene Sorten ausgestellt, die für unsere Landschaftsgärtner von hoher Wichtigkeit sein werden, so Clematis Viticella fl. pl. Lamartine, völlig gefüllt blühend,  Viticella rubra grandiflora, Viticella kermesina und die riesenblumigen Sorten „Princesse of Wales" „Paul Avenel" , "William Kennet'', „Max Leichtlin" u. a.

Translation:
The company Simon Louis frères, Plantières near Metz, had exhibited novelties and rare varieties, which will be of great importance to our landscape gardeners, such as Clematis Viticella fl. pl. Lamartine, completely double flowering, Viticella rubra grandiflora, Viticella kermesina and the giant-flowered varieties “Princesse of Wales”, “Paul Avenel”, “William Kennet”, “Max Leichtlin” and others.

Magazine  (17 Nov 1900)  Page(s) 537.  
 
La Maladie noire des Clématites à grandes fleurs....Les variétés qui été les plus atteintes au Jardin botanique de la Ville sont :
2° Dans le groupe Clematis lanuginosa Ldl. : les variétés Aureliana, Henryi, La France, lanuginosa pallida, M^me Durand, Marie Desfossé, The President, William Blue Gem, Max Leitchlin, Paul Avenel, Kennett.

Book  (1898)  Page(s) 64.  
 
Variétés Horticoles
1er Groupe.—PATENS
Section II. — Lanuginosa.
William Kennett (Jackman). Bleu lavande foncé, à bandes médianes claires.

Book  (1880)  Page(s) 101.  
 
Beschreibendes Verzeichniss der Arten, Varietäten und Hibriden der harten, jetzt in der Gärten cultivirten Clematis in alphabetischer Reihenfolge.
C. William Kennett, Cobbett. — Frühe Lanuginosa-Gruppe.  Blätter dreizählig, Blättchen herzförmig-oval.  Die Blumen haben 16 bis 21 cm im Durchmesser.  Die Sepalen sind 5 cm breit, breit elliptisch-oval, zugespitzt, sich überdeckend, dunkelbläulichlavendelfarbig, an der Basis der Naht ein schwacher Schein von Weinroth; Staubfäden weiss, Staubbeutel purpurlich, an ihrer Basis roth.  Juni bis September.

Translation: Descriptive list, in alphabetical order, of species, varieties and hybrids of hardy garden Clematis cultivars.
C. William Kennett, Cobbett. — Early Lanuginosa group.  The leaves consist of three heart-shaped or oval leaflets.  The flowers are 16 to 21 cm. in diameter.  The sepals are 5 cm. wide, broadly elliptic-oval, acuminate, overlapping; the color is a dark bluish lavender with the bases tinted wine-red; the stamens are white, white the anthers are purplish and red at their bases.  Blooms from June through September.

Magazine  (1877)  Page(s) 272.  
 
Clématites de pleine terre.
Clematis William Kennett (Jackman), s. des lanuginosa; lavande.