Complex sentence: With this subject matter, Kulagina's work combined drawing and graphic symbolism with elements of the photomontage style that had been pioneered by her husband, a combination that distinctively separated her work from Klutsis'.
Split into simpler sentences: With this subject matter, Kulagina's work combined drawing and graphic symbolism with photomontage techniques (that had been pioneered by her husband). It was a combination that distinctively separated her work from Klutsis'.