Ref1

https://books.google.com.my/books?id=-4tlDwAAQBAJ&pg=PA52&lpg=PA52&dq=Teff+%27Dukem%27+yield&source=bl&ots=vyeN_fPc65&sig=ACfU3U0_wx2dLTEoL4AkIT0s3cJsrhOmDg&hl=en&sa=X&ved=2ahUKEwiUlcuhtpzhAhUKrI8KHSezAMgQ6AEwBXoECAkQAQ#v=onepage&q=Teff%20'Dukem'%20yield&f=false