 During his stay Lissitzky also developed his career as a graphic designer with some historically important works such as the books <unk> <unk> ( For the Voice ) , a collection of poems from Vladimir Mayakovsky , and Die <unk> ( The <unk> ) together with Jean Arp . In Berlin he also met and befriended many other artists , most notably Kurt Schwitters , László Moholy @-@ Nagy , and Theo van Doesburg . Together with Schwitters and van Doesburg , Lissitzky presented the idea of an international artistic movement under the guidelines of constructivism while also working with Kurt Schwitters on the issue <unk> ( Nature ) of the periodical Merz , and continuing to illustrate children 's books . The year after the publication of his first Proun series in Moscow in 1921 , Schwitters introduced Lissitzky to the Hanover gallery <unk> , where he held his first solo exhibition . The second Proun series , printed in Hanover in 1923 , was a success , utilizing new printing techniques . Later on , he met Sophie <unk> , who was the widow of Paul <unk> , an art director of the <unk> at which Lissitzky was showing , and whom he would marry in 1927 . 
