Complex sentence: These generalisations have also proven to be the basis for unjustified criticism of his work, Lambourne, "The Art of Bird Illustration" since the nature of scientific illustration places a premium on consistency.
Split into simpler sentences: These generalisations have also proven to be the basis for unjustified criticism of his work (Lambourne, "The Art of Bird Illustration"). The nature of scientific illustration places a premium on consistency.