Source: https://www.researchgate.net/profile/John-Walker/publication/7319868_A_sixth_subunit_of_ATP_synthase_an_F0_component_is_encoded_in_the_pea_chloroplast_genome/links/54d4c1bd0cf246475806494e/A-sixth-subunit-of-ATP-synthase-an-F0-component-is-encoded-in-the-pea-chloroplast-genome.pdf