1 조충호, "수의산과학" 영재교육원 326-348, 1981
2 박형무, "산과학 - 제4판" 군자출판사 607-608, 2007
3 Hendy CR, "twinning in cattle" 38 : 22-27, 1970
4 Cunningham F, "Williams Obstetrics" McGraw-Hill 869-870, 2009
5 Karlsen A, "Twinning rate in Norweigian cattle: Frequency, (co)variance components and generic trends" 78 : 15-20, 2000
6 Gregory KE, "Twinning in cattle: I. Foundation animals and generic and environmental effects on twinning rate" 68 : 1867-1876, 1990
7 Rutledge JJ., "Twinning in cattle" 40 : 903-, 1975
8 Dickerson GE, "Twinning and efficiency of beef production" 3 : 31-33, 1988
9 Johansson I., "The sex ratio and multiple births in cattle" 24 : 183-268, 1932
10 Kinsel ML, "Risk factors for twinning in dairy cows" 81 : 989-993, 1998
1 조충호, "수의산과학" 영재교육원 326-348, 1981
2 박형무, "산과학 - 제4판" 군자출판사 607-608, 2007
3 Hendy CR, "twinning in cattle" 38 : 22-27, 1970
4 Cunningham F, "Williams Obstetrics" McGraw-Hill 869-870, 2009
5 Karlsen A, "Twinning rate in Norweigian cattle: Frequency, (co)variance components and generic trends" 78 : 15-20, 2000
6 Gregory KE, "Twinning in cattle: I. Foundation animals and generic and environmental effects on twinning rate" 68 : 1867-1876, 1990
7 Rutledge JJ., "Twinning in cattle" 40 : 903-, 1975
8 Dickerson GE, "Twinning and efficiency of beef production" 3 : 31-33, 1988
9 Johansson I., "The sex ratio and multiple births in cattle" 24 : 183-268, 1932
10 Kinsel ML, "Risk factors for twinning in dairy cows" 81 : 989-993, 1998
11 Maijala K, "Genetic correlations of twinning frequency with other economic traits in dairy cattle" 107 : 7-15, 1990
12 Cady RA, "Factors affecting twinning and effects of twinning in Holstein dairy cattle" 46 : 950-956, 1978
13 Schillo KK, "Effects of nutrition and season on the onset of puberty in beef heifers" 70 : 3994-4005, 1992
14 Johansson I, "Causes of variation in the frequency of monozygous and dizygous twinning in various breeds of cattle" 78 : 201-234, 1974
15 Eddy RG, "An economic assessment of twin births in British dairy herds" 129 : 526-529, 1991