Although he acknowledged all three men in his Preface and mentions them each about thirty times in the _Account_, it was Kirkman who was most admired by Langbaine and of most use to him. Kirkman's _Catalogue_ of 1671, "_the_ first ... _printed of any worth_," was the principal source of _Momus_, and it, in turn, was based on a catalogue which Kirkman made and published ten years previously.[8] The format of Kirkman's 1671 catalogue followed the general format of his earlier catalogue and of several earlier play lists[9] by arranging the plays alphabetically by title and with some haphazard attempt at chronological order as well, but, as Langbaine described it, "promiscuously _as to those of_ Authors" except for "Shakespeare, Fletcher, Johnson, _and some others of the most voluminous Authors_," whose works were inserted in first place ([A3r]). The catalogue listed eight hundred and eight plays, and its principal orientation was most likely not scholarly but commercial, to list the books which Kirkman had for sale.[10] Nevertheless, Kirkman argued for the completeness of the second catalogue: I really believe there are no more [plays], for I have been these twenty years a Collector of them, and have conversed with, and enquired of those that have been Collecting these fifty years. These, I can assure you, are all in Print, for I have seen them all within ten, and now have them all by me within thirty.[11] Langbaine's first catalogue, _An Exact Account_, was published anonymously and his authorship of this work has been questioned.[12] But he refers to it as his own at least three times (on pages 13, 395 and 409[13]) in the _Account_. Basically, in _An Exact Account_ Langbaine "_Reprinted_ Kirkman's [catalogue] _with emendations, but in the same Form_" ([A3r]), with an added alphabetical list giving authors publishing from 1675 to 1680. As James Osborn has shown, Langbaine perpetuated most of Kirkman's errors, even where Dryden was concerned, still mistakenly attributing to him _Love in a Wood_ and to his brother-in-law, Sir Robert Howard, _The Maiden Queen_ and _Sir Martin Mar-All_.[14] _An Exact Catalogue_, in turn, formed the basis for _Momus_.[15] It has been suggested that Langbaine worked for Kirkman and came into possession of his collection, but the small evidence in _Momus_ is to the contrary: Langbaine lists Kirkman's own play _Presbyterian Lash_ as anonymous, and in the play index he enters _The Wits_ (1672), a collection of drolls Kirkman claimed to have compiled, as "By Sir W. D." and then omits it from the main lists. In the _Account_, _Wits_ is assigned anonymously. At the time of _An Exact Catalogue_ it can only be assumed that Langbaine's attitude toward Dryden was similar to Kirkman's: