"Burning..." (1974) has been reprinted enough that everyone who wants one can easily find it. Ecco is still reprinting it, if you want a new one; Barnes & Noble or Borders probably carries it, or get it on-line from them. Otherwise, newer and older copies show up all the time on ebay. "Burning..." may be his best collection of poetry, and it's nice that it encompasses ~10 years of his stuff. "Dangling in the Tournefortia" (1981) is also excellent, and just about all, if not all, of his "standard" releases are still being printed by Ecco.