Pumpkin seed flour was added to the ingredient database in 2010. The variations pumpkin seed meal, ground pumpkin seeds and milled pumpkin seeds were added in 2014. These are the recipes in the Library containing those ingredients:
Pumpin seed flour - Garlic breadsticks from The Joy of Gluten-Free, Sugar-Free Baking
Pumpkin seed meal - 3 recipes
Ground pumpkin seeds - 11 recipes
Milled pumpkin seeds - 1 recipe
So there aren't very many - if you don't own any of those books then that is why you get zero results.