Brihat Parashara Hora Shastra
अन्योन्यं च मुदा युक्तं फलं मिश्रं वदेत्पुनः । बलहीने तदा हानिः सबले च महाफलम् ॥ २०॥
Weak Grahas cause reduction in good effects, while stronger ones give greater effects.
english translation
anyonyaM ca mudA yuktaM phalaM mizraM vadetpunaH । balahIne tadA hAniH sabale ca mahAphalam ॥ 20॥
hk transliteration by Sanscript