This can be earned in Stage 4-2, Going Mad's "Fleetwood Bounder".
The goal is to totally destroy the RV camper within the time limit. Doing that involves two things: Pressing
to slow down time (and thus the timer), and
to blast the camper with your noxious burps. Basically, it's like a bonus stage similar to old 16-bit arcade games (Street Fighter, Final Fight, etc.).
As you work, you'll notice that coins will bust out of the camper, and occasionally blue pages as well. This presents an issue: You need to get 100 coins and 3 pages, but getting them takes time away from destroying the camper. Worse, the coins and pages disappear after a set amount of time. The solution is to play the level multiple times. Once to focus on destroying the van, and the second+ to focus on coins and pages.
Note that completing the stage with some but not all of the 100 coins still flags the ones you have gotten as 'collected'. If you play the level again, they'll be noticeably different. You can try to get all you can get, exit to save the ones you have collected, then play another round. Keep slowing down and burping, then rush to grab the missing coins or pages you hadn't the previous times.