Combining ability and heterotic grouping of CIMMYT subtropical quality protein maize lines Li MingShun; Zhang ShiHuang; Pan GuangTang; Li XinHai; Xia XianChun; Tian QingZhen; Bai Li Scientia Agricultura Sinica 38(4): 671-677 2005 https://eurekamag.com/research/004/078/004078610.php