1. Generalized Goodwin’s theorems on general coordinates;Aruka,1991
2. Possibility theorems on reswitching of techniques and the related issues of price variations;Aruka,2000
3. Solutions to linear equations depending on a parameter;Bidard;Rivista di matematica per le scienze economiche e sociali/Decis. Econ. Finance,1996
4. Regularity in price changes as an effect of changes in distribution;Bienenfeld;Cambridge J. Econ.,1988