The verb sheet students clamored for. (As much as students clamor for verb sheets.)
My Grünblatt* (yes, "green sheet") contains all the strong (read: irregular) German verbs you need to speak or write about things that have happened. Seriously.
We have cried and pardoned and whistled and suffered and sang and succeeded and stank and enjoyed. And several more beautiful verbs for your reading enjoyment.
If you’re using a German verb not on this list, then you’re either a more advanced German speaker (congratulations), you’ve found a regular verb that works (congratulations), or you’re using an online translator.
Seriously, don’t do that. It’s not helping you like you think it is.
*You provide the green paper.