Perhaps you should try some spelling variations:
ptask » task, ptas, ptaskk, pptask
rptaskk » rtaskk, rptask, rptaskkk, rpptaskk
rptask » rtask, rptas, rptaskk, rpptask
ptaskk » taskk, ptask, ptaskkk, pptaskk
rtaps » rtas, reaps, rmaps, rgaps, rtape
taps » maps, gaps, tape
tas » task, ptas

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((((ptask or ((rptaskk OR rptask) or (rtaps or taps))) or ptaskk) or tas) or ios)-ibg books series.~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((ptask OR ((rptaskk OR rptask) OR (rtaps OR taps))) OR ptaskk) OR tas) OR ios)-ibg books series..
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((ptask or ((rptaskk OR rptask) or (rtaps or taps))) or ptaskk) or tas) or ios)-ibg books series.".
• Adding a wildcard symbol may retrieve word variants: ((((ptask or ((rptaskk OR rptask) or (rtaps or taps))) or ptaskk) or tas) or ios)-ibg books series.*.