Why are so many searches specifically for ? In the standard published edition by Ediciones Espiral Eterna (later distributed by Berben ), the piece is notoriously dense. Page 13 (or measure 13 depending on the typeset) usually contains the most technically demanding passage of the work.
For those looking for the sheet music, several digital archives and official distributors provide access: leo brouwer paisaje cubano con lluvia pdf 13