Good question, and the thread has already surfaced the key fork. It helps to separate two things: the primary sources (free, and they tell you what the tradition actually prescribed) from the modern reframings (which is usually what people mean by "without binding").
On the primary side, all public domain:
The Ars Goetia itself (Lemegeton, Book I) — the Mathers/Crowley 1904 edition, or the older Sloane MSS.
Reginald Scot's Discoverie of Witchcraft (1584), which prints Weyer's Pseudomonarchia Daemonum (1577) — the direct literary ancestor of the Goetia's spirit-list, and the earliest widely available source in English.
The pseudo-Agrippa Fourth Book of Occult Philosophy — the six-stage evocation frame neilwilkes listed (consecration → invocation → evocation → constraint → binding → license) comes straight out of that lineage.
The honest catch is the one neilwilkes is pointing at: the Lemegeton Goetia is built around the constraint model — the circle, the triangle, the lamen, the brass vessel, and (in the Rudd variant) a specific constraining angel per spirit. So "Goetia without binding" is mostly a modern reinterpretation, not something the base text supports. Not a judgment — just where the line falls.
If the modern relationship/pact approach is what you're after, the two names already dropped are the right ones. Jake Stratton-Kent's True Grimoire (2nd ed.) — though Tryp is correct that its spirits are the Grimorium Verum hierarchy (Verum's Three Chiefs and their dukes), not the Lemegeton 72, even where they overlap. And S. Connolly is explicitly modern demonolatry, so read it as devotional-modern rather than historical.