http://www.engvid.com/express-negative-ideas-powerfully/
http://www.perfect-english-grammar.com/inversion.html
http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv293.shtml
http://esl.about.com/od/advancedgrammar/a/inversion.htm
http://fullspate.digitalcounterrevolution.co.uk/efl-advanced-grammar/
http://www.learn-english-today.com/lessons/lesson_contents/exercises/inversion-ex.htm
http://usefulenglish.ru/miscellany/misc-exercise-three
http://www.esl-lounge.com/student/grammar/4g85-inversion-multiple-choice.php http://alfonsohinojosa.es/web/curso5/ejercicios/grammar/rephrasing/5_2_rephrasing_inversion1.htm (sentence transformation)
http://random-idea-english.blogspot.com.es/2011/05/negative-inversion-practice-exercises.html
http://www.englishw.com/FIExercises.php
http://www.perfect-english-grammar.com/inversion-exercise-1.html
http://www.englishtenses.com/exercise/inversion_exercise
http://www.carmenlu.com/sixth/grammar/inversion61.htm
http://www.carmenlu.com/sixth/grammar/inversion_fronting6-1.htm
