Book  (Apr 1993)  Page(s) 227.  
 
Greta Kluis Polyantha, description, 1916, 'Echo' sport; Kluis & Koning.

Book  (Jun 1992)  Page(s) 246.  
 
Greta Kluis Polyantha. Kluis & Koning, 1916. Sport of 'Echo'. [Author cites information from different sources.]

Book  (1958)  Page(s) 145.  
 
Greta Kluis. Pol. (Kluis & Koning, '16.) Echo sport. Dbl., open, carmine-red; cluster. Fol. soft. Vig., bushy.

Magazine  (Jun 1948)  Page(s) 2. trimester, p. 14-15.  
 
D'autres familles moins compliquées de sports dans la classe des vrais polyanthas sont :
3^o Tausendshön a donné un sport Echo, qui lui-même a donné Brillant Echo, Direktor Struve, Eva Teschendorf et Greta Kluis. Ce dernier lui-même a donné Président Hinderberg. 

Book  (1936)  Page(s) 388.  
 
Kluis, Greta (Pol) Kluis & Koning 1916; sport of Louise Walter or Echo; carmine-pink, medium-size, double, cup-form, lasting, cluster-flowered, floriferous, continuous bloom, growth 5/10, bushy, short, Sangerhausen

Website/Catalog  (1929)  Page(s) 43.  
 
Polyantha Roses
Polyanthas are, perhaps the most truly everblooming of all Roses, being scarcely ever out of flower during the whole growing season... They are especially valuable for massing, edging, and to some extent for mingling with other flowers.
Greta Kluis. (Kluis & Koning, 1915.) Medium-sized, double flowers of deep pink, passing to carmine-red, slightly fragrant, produced abundantly throughout the season in small bunches on dwarf, bushy plants with normal foliage. Hardy and dependable.
A deep-colored sport of Louise Walter. At times its globular little blooms look like the old-fashioned strawflowers.

Website/Catalog  (1926)  Page(s) 68.  
 
Polyantha. Grete Kluis (Kluis and Koning 1922). Type of Louise Walter, beautiful carmine-red, for edging and beds.