How to solve it :
Polya, G.
How to solve it : mathematical method.-2nd ed. G. Polya - 2nd ed. - New Delhi: Prentice Hall of India, 2001. - xxi, 253p.
Mathematical recreations.
51-8 / POL
How to solve it : mathematical method.-2nd ed. G. Polya - 2nd ed. - New Delhi: Prentice Hall of India, 2001. - xxi, 253p.
Mathematical recreations.
51-8 / POL