B FH comprehensively outlined and analyzed the nucleosynthesis of the elements heavier than iron by the capture within stars of free neutrons. It advanced much less the understanding of the synthesis of the very abundant elements from silicon to nickel. The paper did not include the carbon-burning process, the oxygen-burning process and the silicon-burning process, each of which contribute to the elements from magnesium to nickel. Hoyle had already suggested that supernova nucleosynthesis could be responsible for these in his 1954 paper. Donald D. Clayton has attributed the lower number of citations to Hoyle's 1954 paper compared to B FH as a combination of factors: the difficulty of digesting Hoyle's 1954 paper even for his B FH coauthors, and among astronomers generally; to Hoyle's having described its key equation only in words rather than writing it prominently in his paper; and to Hoyle's incomplete review of the B FH draft.