While digging for data for this semester's paper, I found "Examining Port Scan Methods - Analysing Audible Techniques". While it's not entirely accurate (never say that something is impossible when discussing network security!), it does give a somewhat comprehensive listing of the types of network scan techniques in use today. As there's a good chance that the author is an Italian hacker, I think the intent was to use "available" vice "audible" throughout the document.
Oh, and please don't confuse scan technique with scan type. "Detection and Characterization of Port Scan Attacks" is a paper which describes the different types of scans (vertical, horizontal, block). It's a short paper but does present a decent syntax for describing the type of scan.