This is the pen calligraphy of calligrapher Huang Ruozhou. The font is cursive.
Huang Ruozhou (1906-2000) was originally named Jicai. No. Ruozhou, born in Shanghuang Town, Liyang, Jiangsu Province. His ancestors were farmers, but his father died when he was young. He relied on his widowed mother to weave and cultivate the land and pawn it for his education. He entered Shanghuang Primary School at the age of seven. The clan members loved him for his intelligence and good drawing, and he was ordered to illustrate the family tree. He was praised as a good person in the village. So he worked hard to paint things, learning everything from figures, flowers and birds, landscapes, and calligraphy, each with its own scale, and was regarded by the elders as a material that could be made.
He is the author of "Quick Writing Methods of Chinese Characters", "Techniques of Flower and Bird Painting", "Huang Ruozhou's One-stroke Calligraphy", "Huang Ruozhou's Relationship with Calligraphy and Painting", and the movies "Teaching Chinese Painting" and "Teaching Chinese Calligraphy".
This picture should be from "How to Write Chinese Characters Quickly" or "How to Write Chinese Characters Quickly".