American Institute Time Hull Form {= AITH Form}

exponent form Newton backward interpolation operator in power exponent form

form factor [= wave form factor]

metric normal form of quadratic form

the canonical form of a quadratic form

Unitary-form (U-form) firm

represeuting a complete form sence f rom one thousaud Chinese feet and a detail form from one hundred Chinese feet

240 spark plug gas engine

5-valve spark ignition engine

AC spark

AC spark tester

Activation-spark

active spark

Advanced Spark

Advanced Spark Timing

air-gap spark

alternating spark-over voltage

Anodic Spark Oxidation

anti-spark