Valentín Albillo

• Long live to the HP 71b
• Long Live the HP-34C !
• Boldly Going - Identifying Constants
• Boldly Going - Matrix Square Root
• Small Fry - Primes A'counting
• Long Live the HP-35 !
• Long Live the HP-25 ! 
• 25 Years of Othello for the HP 71b

• HP-71B Short & Sweet Sudoku Solver for the HP 71b
• HP-71B Sudoku Solver's Sublime Sequel for the HP 71b
• HP-71B Sudoku Generator & Coach for the HP 71b
• Long Live the HP-16C ! 
• HP-42S Long Live the HP-42S ! 
• HP-71B Math ROM Baker's Dozen (Vol. 1)
•  HP-71B Math ROM Baker's Dozen (Vol. 2)

• HP-71B Fantastic FOUR 

• HP-71B Modest Mater
• HP-41C Long Live the Advantage ROM !
• Short and Sweet Math Challenges
• HP-15C Nth-degree Polynomial Fitting
• HP-15C Long Live the HP-15C ! 
• HP-12C Tried & Tricky Trigonometrics
• HP-12C Serendipitous Solver
• HP-12C: Long Live the HP-12C !
• HP-11C Long Live the HP-11C !
• Short and Sweet Math Challenges

Valentín Challenges:

#10: Counting Beans

#11: Who's Next ?

#12: Squaring Cubes

#13: Adding up to Infinity

#14: Cooking Conjectures

#15: Spring 2006 Special

#16: Thinking Square !

 #17: The Feast

 #18: 2007's Spring Special

 #19: Surprise !