c-C₃H₂ rotational diagrams of the sources in the CrA survey where at least two c-C₃H₂ lines were detected. The ortho lines are filled in the left half, the para lines are filled in the right half, and the lines that are blends of ortho transitions and para transitions are completely filled. All data points are 1.3 mm lines observed with APEX. (A colour version of this plot is available in the online Journal.)