Oregon State University. Extension Service; Mansour, N. S.; Raab, Carolyn A. ([Corvallis, Or.] : Oregon State University, Extension Service, 1995-09)
Of the four main types of lettuce,
three are easy to grow: looseleaf,
butterhead (Bibb), and romaine
(cos). The fourth kind, called
crisphead or iceberg lettuce, demands
slightly more exacting climatic and
cultural ...