Help us neuter and vaccinate stray kittens.

Two weeks ago we found 3 little kittens in our backyard. They were really sick and they couldn't eat because their mouths were full of ulcers. We took them to the vet, we gave them medication for 2 weeks and the kittens are now healthy and playful. The thing is that they seem to really like us and we would love to keep them but we must neuter them and give them their first vaccination and we can't afford the cost. We have spent a fair amount of our budget for their treatment and medication. Please help us keep these wonderful creatures, we really love them!