B. D. Ezell & M. S. Wilcox (1959),
Loss of Vitamin C in Fresh Vegetables as
Related to Wilting and Temperature

Anna Korus & Zofia Lisiewska (2011),
Effect of preliminary processing and method
of preservation on the content of selected
antioxidative compounds in kale

S. Pandrangi & L.F. Laborde (2004),
Retention of Folate, Carotenoids,
and Other Quality Characteristics in
Commercially Packaged Fresh Spinach

J. C. Rickman & C. M. Bruhn & D. M. Barrett (2007),
Nutritional comparison of fresh, frozen, and canned fruits
and vegetables II. Vitamin A and
carotenoids, vitamin E, minerals and fiber

University of Chester (2014),
Antioxidants in fresh and frozen fruit and vegetables:
Impact study of varying storage conditions

L. Neri & M. Faieta & C. D. Mattia & G. Sacchetti
& D. Mastrocola & P. Pittia(2020),
Antioxidant Activity in Frozen Plant Foods:
Effect of Cryoprotectants, Freezing Process
and Frozen Storage