Check authorized e-retailers or the publisher’s direct portal to purchase legal e-book versions or official digital companions.
Classification, definition, and need for dosage forms.
Some public libraries list their physical copies online, which can help you locate a copy to borrow. For example, the NITI Aayog Library in Delhi has a record of the 4th edition (published in 2008) available in its collection for reference, identified by its ISBN 81-85731-32-2.
If you are a student looking for the specific text, I recommend the following legitimate sources: