9Add. J Tunnel housing of pigs in Livestock Environment IV. Fourth International Symposium [ M ]. Michigan: American society of Agricultural Enginneers, 1993 : 1040 - 1045.
10Philippea F X, Laitat M, Canart B, et al. Comparison of ammonia and greenhouse gas emissions during the fattening of pigs, kept either on fully slatted floor or on deep litter [ J].Livestock Science, 2007, 111 (1/2): 144 -152.