How can i get my peppered cory to mate/breed?

well my panda corys mated and i have no idea what i did to make them breed. my tank was mostly panda corys other than the otos so that might be something that made them breed. also i fed them blood worms often. and according to my fish book, have a trio of one female and two males. signs of spawning is the "t-position" where the female aligns her body at right angles with the chosen male and will nuzzle his vent. they lay their eggs on broad surfaces like a broad leaf, rock or the wall of the aquarium. the time it takes the eggs to hatch depends on the temperature of the tank. and that's all i got from the book. good luck!