41. There are also piano works that are from Bart�k's first and second set of opus numbers . 42. Hausmann's own compositions are now completely forgotten, but they included at least 41 opus numbers . 43. Within each group there are first works with opus number and then the works with an EM code. 44. This way it could happen that the same opus number was given to more than one of his works. 45. In other cases, the same work was given as many as three different opus numbers by different publishers. 46. The true tally is well over 500 surviving works since many opus numbers comprise two or more distinct works. 47. This work, one opus number , was printed in Amsterdam in 1712 by the famous publisher Estienne Roger. 48. :: See Catalogues of classical compositions # Opus numbers for some reasons why opus numbers will not do. 49. :: See Catalogues of classical compositions # Opus numbers for some reasons why opus numbers will not do. 50. This work was never given an opus number , and only the scherzo seems to have ever been published .)
