Complement clauses of reken in the sense of 'think' (or as a speech verb) and of wantim 'want (something)' do not take a complementizer. The latter are rare and possibly acrolectal; more usually, a manipulative verb like telim 'tell someone (to do something)' would be used which usually takes a quotation as a complement or (possibly acrolectally) a verb introduced by the complementizer tu.
Source: Sandefur & Sandefur 1982: 67
Source: Galmurr & Willika 1996
Source: Angelo et al. 1998a