{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"$id": "http://example.com/schemas/three",

	"type": "object",
	"properties": {
		"children": {
			"type": "array",
			"items": {
				"anyOf": [
					{ "$ref": "http://example.com/schemas/one" },
					{ "$ref": "http://example.com/schemas/two" }
				]
			}
		}
	}
}