Most ice cream books contain quite a few recipes without dairy. The new Perfect Pops book has about 20 of the 50 recipes free of dairy, with some made with soy or coconut milk. It's not indexed yet though will be soon. An indexed book is the recent book by Fany Gerson, Paletas, which also has about 20 dairy free ices though more on the sorbet/granitas side than ice creams.
A way to see all the recipes available in cookbooks is to search the EYB Library by Only Show filters - Recipe type; Ice creams & frozen desserts and exclude Ingredient; Dairy (click the green cross to turn it into a red minus). Not all the recipes you see will actually be dairy-free as small amounts of milk are considered a store-cupboard ingredient. You get 2,391 results which include a lot of sorbets. To exclude the sorbets or granitas listed just enter -sorbet or -granita in the search terms box.
You can also add the word soy (or coconut or almond) to the search terms box and you will see a much smaller number of recipes. Many of these come from Veganomicon which I don't have so cannot personally recommend. But vegan cookbooks would be a good source for dairy-free recipes. There are a couple just on frozen desserts called The Vegan Scoop and Vice Cream. Hopefully someone who owns either can give you the scoop (hah!) on these books.