title: A positive correlation between population size and egg-content in Metastrongylus apri (Gmelin, 1790).
mesh_terms: D000818:Animals; D005260:Female; D008168:Lung; D008297:Male; D008681:Metastrongyloidea / Q000254:growth & development*; D010270:Parasite Egg Count; D012098:Reproduction; D013552:Swine