_id,doi,title
3670, 10.1111/j.1558-5646.1981.tb04966.x,A chromosomal cline in the grasshopper Podisma pedestris
3671,10.1038/hdy.1981.86,The width of the hybrid zone in Caledia captiva
4132,10.1016/0020-0190(81)90053-3,On the intersection of Orthogonal objects
4133,10.1016/0304-3975(81)90103-1,A space-optimal solution of general region location
4332,,Hybrid zones and speciation
4333,10.1038/hdy.1981.98,The genetic basis of hybrid inviability between two chromosomal races of the grasshopper Podisma pedestris