Gaya APA
Schwab, Klaus. (2017).
The Fourth Industrial Revolution .
USA:
portofolio penguin.
Gaya Chicago
Schwab, Klaus.
The Fourth Industrial Revolution.
USA:
portofolio penguin,
2017.
Text.
Gaya MLA
Schwab, Klaus.
The Fourth Industrial Revolution.
USA:
portofolio penguin,
2017.
Text.
Gaya Turabian
Schwab, Klaus.
The Fourth Industrial Revolution.
USA:
portofolio penguin,
2017.
Print.