"It is impossible to say how many flute sonatas were composed by George Frideric Handel, but the correct number is somewhere between none and eight. There are many reasons for the confusion: some of the sonatas were originally written for other instruments, some have uncertain authenticity, some contain borrowings from other Handel works, and some were published (in an altered form) without Handel's knowledge. At least six of the sonatas are known to contain music written by Handel, although he may not have intended some of them to have been played by the flute.
The main source of the sonatas is the 1727 publication Sonates pour un traversiere un violin ou hautbois con basso continuo composées par G. F. Handel, allegedly by the Amsterdam publisher Jeanne Roger (who had died in December 1722), however the publication was made by the printer John Walsh..." Read more, here.