http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/regcom2.htm
http://www.montsemorales.com/gramatica/ComparSuperlat.htm
http://www2.arnes.si/~oskplucija4/ces/adjectives3.htm
http://testy.mzs-vb.cz/spustit-test.php?id=361
http://www.english-4u.de/comparison_ex2.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_sentences.htm
http://www.learnenglish.be/gr2_degrees_study.htm
http://www.englishexercises.org/makeagame/viewgame.asp?id=316