Umlaut is the accent put above the lettes U, O and possibly a few others in German. Its denoted by two .. above the letter and changes the pronounciation of the letter. Hopefully my cut and paste worked
oops, sorry. yes, umlauts are two little dots above the vowel, to make you say the word slightly differently. kur should have an umlaut, and if you can't do the umlaut (as i can't on this keyboard!) you put an 'e' after the letter that needs the umlaut, hence 'kuer'. umlaut means "say louder", sort of thing!
luhmuhlen (supposed to have an umlaut over 2nd u) = luhmuelen, etc etc.
so it's "rueckwaerts", but that looks unpronouncable, i know!