Perhaps you should try some spelling variations:

• numerical approximation »
  • numerical approximations (Expand Search)
  • geometrical approximation (Expand Search)
  • numerical application (Expand Search)
• polynomial numerical »
  • polysos numerical (Expand Search)
• approximation scheme »
  • approximation semi (Expand Search)
  • approximation when (Expand Search)
  • approximation sums (Expand Search)
• level approximation »
  • element approximation (Expand Search)
  • field approximation (Expand Search)
• polynomial level »
  • polynomial kernel (Expand Search)
  • polynomials bessel (Expand Search)
  • polynomial models (Expand Search)