VERTEBRATES IN TIME
when each group appeared · five hundred million years on one axis
Free
BASIC PHYSICS FORMULAS
fifteen formulas · every letter explained beneath it
Free
ANIMALS
the main branches — from comb jellies to chordates · who is actually related to whom
Free
THE TREE OF LIFE
who sits inside whom · where animals, fungi and plants actually are
$1.50
VERTEBRATES
from lamprey to bird · and why "fish" and "reptiles" are not groups
Free
MORSE CODE
26 letters and 10 digits · dot, dash
Free
PHONETIC ALPHABET
the ICAO standard · for radio and telephone
$2.50
PAPER SIZES
the A series · from A0 to A6
$1.50
SI PREFIXES
from quetta to quecto · twenty multipliers
$1.50
BICYCLE CLASSES
frame, wheel by ISO 5775 and handlebar — three signs of a class, and what the frame is rated for
Free
CAR CLASSES
segments A to F by length and bodies by box count — how to name any car you see
Free
MOTORCYCLE CLASSES
rake, trail, wheelbase and seat height — six classes drawn at one scale
Free